Royals trade Carlos Santana to Mariners, promote top prospect Vinnie Pasquantino

The Mariners have acquired first baseman/designated hitter Carlos Santana and cash from the Royals in exchange for right-handers Wyatt Mills and William Fleming, per a team announcement. The trade paves the road for the Royals to take an overdue look at top prospect Vinnie Pasquantino, whose contract has been formally selected from Triple-A Omaha, according to the team. Right-hander Ronald Bolanos has been designated for assignment in order to open a spot on Kansas City’s 40-man roster.

Monday’s trade closes the book on a generally underwhelming Kansas City tenure for Santana, who inked a two-year, $17.5MM contract in advance of the 2021 season but has yet to round into the form that made him such a valuable contributor for years in Cleveland. The switch-hitting 36-year-old tallied 871 plate appearances with the Royals and posted just a .215/.326/.341 batting line — about 12% worse than league-average after weighting for park and league, by measure of wRC+.

Santana managed to turn things around in recent weeks, however, and has shown enough this month for the Royals to take a low-cost look now that they suddenly find themselves in need of a first baseman. Ty France, Seattle’s most consistent hitter this season, recently landed on the injured list and figures to be out for a good bit longer than that 10-day minimum, given the diagnosis of a Grade 2 flexor strain. Santana shouldn’t be expected to fully replace France’s brilliant .316/.390/.476 batting line, but he’s managed a .298/.405/.468 output himself over his past 27 games and 111 plate appearances.

In all likelihood, the Royals are paying the vast majority of what remains on Santana’s contract. He’s still owed the balance of this year’s $10.5MM salary (about $5.8MM), and that number will increase based on plate appearances. Santana, who already has 212 plate appearances this season, will earn an additional $75K for every 25th plate appearance from 300 to 525.

It’s not the first time the Mariners have acquired Santana, though whenever he takes the field in a Mariners jersey, it’ll be his first actual game with the team. Seattle actually acquired Santana alongside J.P. Crawford in the deal that sent Jean Segura, Juan Nicasio and James Pazos to the Phillies back in Dec. 2018. However, not two weeks later, Santana was traded to Cleveland in the three-team swap that brought Edwin Encarnacion to Seattle. Encarnacion spent a half season slugging as the Mariners’ designated hitter before being flipped to the Yankees for righty Juan Then.

This time around, it’ll be a pair of right-handers going to Kansas City in exchange for the final three-plus months of control over Santana. Of the two righties in question, only Mills has big league experience thus far. The 27-year-old has pitched a total of 21 1/3 frames over the past two seasons but struggled to a 7.59 ERA with worse-than-average strikeout and walk rates in that time (17.3% and 10.2%, respectively).

Mills, the No. 93 overall pick in 2017, has more interesting but also inconsistent numbers in the upper minors. He fanned a whopping 44.7% of his opponents through 28 2/3 innings of Triple-A ball last year, for instance, but that rate has been halved so far in 2022 over the course of 19 2/3 innings. There’s no velocity change between his ’21 and ’22 campaigns, though Mills did throw more fastballs at the expense of some slider usage during this year’s small sample of 8 2/3 big league innings. The 6’4″ righty has never ranked as one of the Mariners’ very best prospects, but Baseball America has listed him among Seattle’s top 25 farmhands dating back to the time he was drafted.

Fleming, meanwhile, is a 23-year-old righty whom the Mariners selected in the 11th round just one year ago. He generally hasn’t been considered among the Mariners’ best prospects either — though FanGraphs’ Eric Longenhagen did tab him 28th earlier this year — and has posted fairly pedestrian numbers in Class-A Modesto despite being a former college arm who’s older than his average opponent at that level. So far, Fleming has tossed 67 2/3 innings over 14 starts and logged a 4.92 ERA with a 20.7% strikeout rate against an 8.4% walk rate.