The biggest X-factors on every MLB roster for 2025

There might not be a more dynamic player in baseball than Carroll, but he regressed last season after winning the 2023 NL Rookie of the Year. The speedy outfielder was able to find his game late in the year after struggling early, and the Diamondbacks hope his struggles are entirely behind him.

Strider needs no introduction as one of the top pitchers in the game, but his timetable for return is murky as he makes his way back from Tommy John surgery. His return and effectiveness could go a long way in determining Atlanta's success this season.

The first overall draft choice in 2022, Holliday struggled in his MLB debut for the O's last season. The team is still counting on him to contribute in 2025, and Holliday has the ability to be an offensive force if his minor-league numbers carry over.

One of Boston's top prospects, Campbell has a chance to compete for the team's second base job in Spring Training and can also help at shortstop, third base, and the outfield. He hit .330-20-77 with 24 steals between three levels last season.

Crow-Armstrong struggled at the plate upon his arrival last season, but made up for it with elite defense in center field. If his offense eventually progresses, the Cubs could have a superstar on their hands with 20/20 ability based on his minor league track record.

The centerpiece of Chicago's trade deadline last year, Vargas struggled after being acquired from the Dodgers. His minor league history shows excellent hitting potential, and the White Sox can afford to give the 25-year-old more runway as they rebuild.

McLain made waves in his rookie season in 2023, but didn't make an MLB appearance last season due to injury. He gained versatility in the outfield during the offseason, and could contribute all over the field for the Reds in 2025.

Center field was a problem for much of last season in Cleveland, but DeLauter could be the answer. After an injury-plagued 2024 season, he hit .340 at the Arizona Fall League and could win a roster spot in Spring Training.

Marquez has been Colorado's ace for much of his career, but has made only five starts over the last two seasons due to Tommy John surgery and setbacks. The Rockies hope he has an entire, healthy season ahead of him and can bounce back to his former All-Star form.

Arguably the best pitching prospect in baseball, Jobe made his MLB debut in relief last season but his future is as a starter. He has a chance to make a big contribution for the Tigers this season.

Garcia was a key part of Houston's starting rotation from 2021-2023 but has struggled to return from Tommy John surgery. The Astros don't expect Garcia to be ready for Opening Day, but he could still make a difference this season after the team lost Justin Verlander.

Pasquantino has been a key part of KC's lineup since arriving in 2022, but injuries have plagued him. He was limited to 131 games last season, but still had 19 home runs and 97 RBI. A full season of health could help him turn in All-Star numbers.

Detmers' career has stagnated, as the former first-round pick was demoted to Triple-A last season and posted a 6.70 ERA in the majors. His stuff remains excellent, but the lefty needs to fix his command issues. The Angels could compete this season if it happens.

A star middle infielder in Korea, Kim is slated to become LA's starting second baseman after they traded Gavin Lux. Kim was an excellent batting average hitter with great speed and defense in Korea, and he hopes to replicate his results for the loaded Dodgers.

A workhorse and ace in Miami from 2019-2023, Alcantara missed all of last season due to Tommy John surgery. The pressure is on Alcantara to find his old form fast after the Marlins traded Jesus Luzardo and lost Braxton Garrett to injury.

Milwaukee's first-place finish in the NL Central last season was more impressive, considering they did it without Woodruff, who missed the year due to shoulder surgery. His status for the start of the year is unclear, but the former ace could be a difference-maker again if he returns healthy.

Wallner got off to a slow start last season after his powerful 2023 season, but his numbers eventually get back on track after getting promoted late. He has rare power, hitting 29 home runs in only 580 career plate appearances. Wallner has a chance to carry the Twins lineup this season if he shows more consistency.

The former Yankees closer, Holmes is set to be a starting pitcher for the crosstown rivals this season. His power sinker could translate well to the new role, and the Mets need his contribution after losing multiple pitchers in the offseason.

Dominguez's return from elbow surgery last season was a slow go, but it appears they're counting on him to be a regular in 2025. The former top prospect will have high expectations as the team tries to get to a World Series.

Wilson showed remarkable minor league production last season, hitting .433 in 53 games. However, his MLB debut was sidetracked by a hamstring injury. The team is still hopeful he can be a table setter as they move to Sacramento.

Luzardo has been an ace when healthy for much of his career but continues to have issues staying on the field. He missed most of last season with a back injury, though Philly hopes he can rebound as a backend starter in 2025.

Cruz returned from a fractured ankle last season but was shifted to center field late in the year. The team views him as their long-term center field, but there could be more potential in his offensive game after becoming a 20/20 man last year.

Tatis returned to the All-Star last year, but was limited to only 102 games due to a leg injury. He's yet to regain the elite form he showed before a PED suspension and shoulder surgery in 2022, though Tatis is only entering his age-26 season.

The Giants signed Lee for more than $100 million last season, but he was limited to 37 games due to a shoulder injury. He has leadoff skills and excellent defensive potential as the Giants look to return to the playoffs.

Washington finally gave up on Robles last season, but he found his footing in Seattle. He hit .328-4-26 with 30 steals in 77 games, and is likely to see regular playing time in 2025. Robles' speed and defense could make a difference for what has been an anemic offense in recent years.

The Cardinals former top prospect, Walker's first two seasons haven't gone as planned. He did make progress late last year, but finished the year hitting only .201 in 51 games. After reworking his swing in the offseason, the Cardinals are counting on Walker to find his form in 2025.

Lowe had a breakout year in 2023, becoming a 20/20 man. Unfortunately, he was limited to 106 games last season due to multiple injuries, and his overall numbers took a hit. After a quiet offseason, the Rays need Lowe to rebound.

DeGrom is the baseball pitcher in baseball when healthy, but he last threw over 100 innings in 2019. The Rangers are hopeful he can put together a healthy season and lead their rotation.

After three consecutive 20-plus home run seasons from 2021-2023, Bichette struggled at the plate last year. He heads into a walk year, likely motivated to put last season behind him and help the Jays.

Abrams had a strong season in 2024, but his year ended on a sour note. He was effectively suspended after some off-field issues late in the year. The Nats have had a busy offseason but are counting on Abrams' full commitment.