One rookie each MLB team will be counting on in 2019

Sherfy made a nice impression in his brief work in Arizona last season, posting a 1.65 ERA over 15 games, a mark that nearly matched his efforts at Triple-A Reno on the year. With the bullpen being a black eye that played a big part in the Diamondbacks’ failure to return to the postseason, his development in 2019 could be an essential part of the team’s success. His experience as a closer in the minors could see him eventually be considered for the role.

While the Braves already have an impressive young talent on the hot corner in Johan Carmego, it is Riley who is the most enticing long-term prospect still in the Braves system. Although he battled knee injuries in 2018, he still showcased an undeniably exciting presence at the plate. Riley connected for 19 home runs and 30 doubles on the year and is preparing to extend the top-tier youth movement in Atlanta next summer.

With the Orioles undergoing as pronounced of a rebuilding effort as any team in the American League, Stewart should get ample opportunities to prove himself next year. While the O’s will likely host a handful of their best prospects over the next year — including Ryan Mountcastle and Yusniel Diaz — Stewart likely has the inroads to making an impact first. He produced a .550 slugging percentage over 47 at-bats in 2018, and with a strong spring he could open the year in left field.

Predictably, there is little for rookie impact on much of the top-tier Red Sox roster. However, the bullpen is an exception, as it continues to be a work in progress. Poyner can become the lead southpaw out of the Boston pen as soon as next year. He struck out 24 over 22.1 innings in 2018, armed mainly with a distinguishable breaking ball and solid fastball.

The Cubs could have used Alzolay’s plus stuff down the stretch last season, as they sought to find options to up the ante in their bullpen. A lat injury brought his 2018 to an early end, but the upcoming year should see him break through to the Chicago rotation in some capacity. His secondary offerings need some further maturity, but with a fastball that can touch the upper-90s, he’ll be able to miss bats from Day 1.

Of all the talents in the minor league ranks, Jimenez brings the most fearsome pure power of all to the plate with him. He averaged 11 home runs per 54 games between the AA and AAA levels, connecting for a .961 OPS at the highest levels of the minors. Jimenez has nothing else to prove as a minor leaguer and should be inserted at the heart of the White Sox lineup for the long-term in the early stages of 2019.

2018 was supposed to be the year that Senzel brought his fantastic all-around bat to the Reds infield. Although he did hit .310 on the year, he made it to the field only 44 times due to bouts with both vertigo and a torn finger tendon. While the Reds infield is currently a crowded scene, featuring three All-Stars, Senzel’s bat is a long-term investment that the Reds will find room to accommodate.

With the Indians being open to shuffling the deck around their prized starting staff, there will soon be openings for talented young arms throughout their system. Chief among those is McKenzie, who held opponents to a .191 average over 90.2 Triple-A innings. While he may stay in Akron in the early stages of the year, McKenzie could make a partial season impact for a contending Indians club, along the lines of what the Cardinals’ Jack Flaherty and the Dodgers’ Walker Buehler did in their rookie campaigns.

Rodgers has been Colorado’s top prospect since the day he was selected by the club with the third pick in 2015 draft. Now four years later, with D.J. LeMahieu a free agent, a clear opportunity is ahead for the talented infielder. Rodgers possesses the ability at the plate to make a quick impact, especially in Coors Field, and he could be at the heart of the NL Rookie of the Year race.

With the Tigers in the midst of a pronounced rebuilding, many parts of their system will get a chance to stake their claim at Comerica Park. Stewart is off to the fastest start, showing a powerful bat that could bring a much-needed, game-changing effect to the Tiger lineup. After connecting for 23 AAA homers, Stewart hit for an impressive .267/.375/.417 split based around balancing power with solid plate discipline (10 walks vs. 13 strikeouts).

With fellow prospect Forrest Whitley being the minor’s top pitcher, it could be argued he could make the biggest impact on the Astros’ 2019 fate. However, with Marwin Gonzalez likely relocating this winter, a full-time role awaits Tucker much earlier in the year, increasing his odds of making a longer-term impact. Tucker has the tools to become the latest in the line of homegrown stars for A.J. Hinch’s club, and he could take advantage of the generous left field porch in Minute Maid Park.

The Royals bullpen needs as big of an overhaul as any in the game, and it's a place where Lovelady could offer some immediate assistance. Armed with a solid fastball/slider repertoire that has been aided by a bump in his velocity over the past few years to the mid-90s, Lovelady has a chance to be an immediate matchup impact against lefties, with the potential to mature into a closer down the road.

The Angels already existent pitching woes took another big hit when Shohei Ohtani was forced into Tommy John surgery that will cost him 2019 on the mound. While they will be forced to address some of that void with external options, turning to the organization’s top pitching prospect in Canning would be a well-served decision as well. A mature hurler who blew through High-A and Double-A bats in 2018, he could make his way to Anaheim by mid-season if he makes the expected strides against Triple-A foes after a difficult debut at that level last summer (3-3, 5.49 ERA).

Although the presence of Yasiel Puig, Cody Bellinger and Joc Pederson, among others, complicates things some, Verdugo’s all-around skill set deserves a spot in the L.A. mix by next spring. He can hit to all fields, has a gifted eye at the plate and a powerful throwing arm and range in the field to boot. The Dodger outfield is a crowded scene, but with Dave Roberts’ dedication to putting his entire roster to use, he will find a way to employ Verdugo’s many talents.

Alcantara emerged in September as clearly the most gifted arm on the Marlins staff, so much so that it is not a stretch to anoint him as the best weapon the organization possesses on the mound. While he has a way to go regarding his control and efficiency, Alcantara is guaranteed to be heavily relied upon in some capacity next year. Whether it be in the starting staff or the backend of the bullpen, time will tell.

Hiura’s mature bat has quickly pulled him upward throughout the ranks of the Milwaukee system. After hitting .313 over his first 165 professional games and putting on an especially strong show in the Arizona Fall League this year, Hiura’s rapid rise may land him in a Brewers uniform soon. A solid defender who profiles as a plug-and-play bat out of the No. 2 slot in the order, Hiura could add yet another efficient boost to the Brewers’ productivity.

The makeover of the Twins infield has opened up a place for the long-awaited arrival of Gordon, the club’s top overall pick in 2014. While his bat regressed after reaching Triple-A Rochester (.212 average over 99 games), he truly lies somewhere between there and the .333 mark he carried at Double-A in the same year. Gordon’s athleticism and speed will allow him to learn on the job at the MLB level while still bringing upside with his speed and glove work.

Alonso’s bat possesses some of the most enticing upside of any on the brink of reaching the majors. He possesses raw power that plays well in-game and is heightened by his mature eye at the plate as well. Alonso could be a middle of the lineup guy, as his .976 OPS since 2017 has put a stamp on the reputation he carried over since his days at the University of Florida. The battle for first base supremacy between Alonso and Dominic Brown could be one of the most interesting of the spring at any camp.

Sure, Sheffield may resemble something of a young, left-handed Bartolo Colon physically, but he also could make the same type of impact as Colon did two decades ago. Sheffield has a ready-to-go trio of pitches in his arsenal already, all of which can function as out pitches. Should the Yankees choose to, Sheffield could stand in as an option to upgrade their starting staff from Opening Day 2019 onward.

The A’s have a need in center field and just the right kind of player to address it in Mateo. The 23-year-old has an elite level of athleticism, the level of which allowed the organization to move him from shortstop to the heart of the outfield last year, which he took to well. While he may not immediately head to the top of the Oakland outfield when he arrives, the speed which has allowed him to steal 259 bases as a minor leaguer will help him to make an impact from the top or bottom of the lineup.

Sanchez could be the most breathtaking arm to reach baseball next year, no matter how he is used. While the organization has been extremely careful in deploying its most prized prospect, limiting him to 95 innings or fewer as a teenager, 2019 could be the year the handcuffs come off. Sanchez is blessed with two above-average fastballs, along with a changeup that has shown to be ahead of its time. With the Phillies angling to remain in the pennant chase for the duration of 2019, having Sanchez to leverage wherever his incredible stuff is needed is a key.

With Jordy Mercer’s health and productivity on the decline again in 2018, the opportunity is there for the shortstop position to be seized. Newman could have the best chance at doing so internally, having already gotten a shot toward the end of 2018. While he didn’t blow anyone away with his early returns — .208 average over 97 plate appearances and 23 strikeouts against four walks — the .350 on-base percentage and annual double-digit stolen base figures he accumulated during his rise through the minors has bought him some investment faith.

Tatis Jr. holds the unique distinction of being not only the second-best son of a former major leaguer making his way toward the bigs but also arguably the second-best overall prospect as well. It will likely take only a month in the season for Tatis’ time as a prospect to end, for contractual reasons. The multitooled shortstop can do it all, despite not turning 20 until January. His upside could give him the ability to make a Corey Seager-like impact as a rookie, although his development path could be in line of that of Manny Machado due to his 6-foot-3 frame.

Due in part to injuries and to age taking its toll, the Giants starting staff is headed toward a youth movement very soon. Anderson is poised to be one of the main contributors to that effort after an impressive first season as a starter in 2018. He possesses a solid all-around offering, with a sinking fastball that produces ground balls at a rate that will find a friendly home in AT&T Park.

Lewis has long been the top prospect in the Mariners system, as he has been able to gradually allow his considerable skill set to mature. But with Seattle potentially headed toward a rebuilding effort, the time may be now for Lewis to bring his athleticism and upside bat to the northwest. Although center field may be earmarked for the recently acquired Mallex Smith, Lewis can easily slot into left field opposite of Mitch Haniger by next summer.

If it seems as if Reyes has been on the verge of joining the Cardinals' rotation for the past three years now. The pathway of the ultra-talented righty has been blocked by season-ending injuries in two of the last three seasons, with a return from Tommy John surgery being cut short when he tore a back muscle four innings into his return to the Cardinal rotation. Despite this, the potential he possesses remains tantalizing, especially for a St. Louis pitching staff that is already bursting with homegrown talent.

The smooth ascent of Honeywell toward the Rays rotation was quickly derailed early in 2018 when he underwent Tommy John surgery during spring training. He is expected back in the Tampa rotation this summer, where he would become a needed addition. His return would go a long way toward stabilizing the Rays rotation, which had become fairly creative in filling starts throughout the year. His wide-spanning arsenal is highly adaptable and should make him instantly reliable in the middle of Kevin Cash’s rotation.

While it is indeterminate if Hearn is going to be a starter throughout his career or a relief option, what is certain is he has the stuff to succeed at the next level. The fact that he can live in the upper 90s and is suited better to be fastball/slider type currently makes it seem as if the bullpen could be the best place for the 24-year-old to start. With many of the Rangers' top prospects being at the lower rungs of their system, he could have a hastened path to Arlington with a good showing in the early parts of the season.

There has not been a better pure-hitting prospect than Vlad Jr. in at least the last decade. He batted over .400 for four months last year and finished with a 1.049 OPS over 91 games between the Double- and Triple-A levels. However, there is still more to come, as he has room to develop as a pure power hitter. The future of the Blue Jays lies squarely in his hands, as he will become an instant headline star from the moment his name first appears on a regular-season lineup card.

The Nationals' incredible run of being home to precocious young outfield talent is set to continue next summer, with Robles taking over in center field. A legitimate five-tool talent with MVP upside, Robles is a table-setting speedster who has defensive upside to match his flash at the plate and on the base paths. After dealing with a scary elbow injury that cost him half of 2018, Robles made an affirming impression in a 21-game MLB sample, producing an .874 OPS.