A KC Royals rookie is replacing Brad Keller tonight

Whit Merrifield, a player many thought the KC Royals would never trade, found himself packing 16 days ago when the team shipped him off to the Blue Jays with little time remaining on the annual trade deadline clock. As the news swirled around player and club, almost lost in the tumult was who the Royals received in return.

And over two weeks later, it may still be the case that many Royals followers can’t name the two players Kansas City traded for.

Samad Taylor, a versatile infielder-outfielder, is one. On the Injured List since before the Royals and Jays made the Merrifield deal, he hasn’t played yet for Triple-A Omaha.

But pitcher Max Castillo, the other half of the “get” for Merrifield, has. He’s 0-0 with a 9.82 ERA and five strikeouts in 3.9 innings since the Royals acquired him. He was scheduled to pitch for the Storm Chasers Wednesday night, but didn’t.

That’s because he’s starting tonight for the Royals against Tampa Bay, a decision the Royals made in conjunction with Wednesday’s transfer of rotation mainstay Brad Keller to the bullpen.

Castillo is a rookie, but this assignment won’t be his major league debut.

KC Royals pitcher Max Castillo won’t find a big league mound unfamiliar.

Tonight’s start against the Rays will mark Castillo’s 10th major league appearance of the 2022 season. He pitched nine times (two starts) with a 3.05 ERA and no decisions for the Blue Jays before they dealt him to Kansas City. He held Tampa Bay scoreless in 3.1 innings over two straight relief outings in early July, but the Royals tagged him for three runs in three innings when he started against them July 16. He’s fanned 20 and walked only five in 20.2 innings.

He was also 3-1, 3.10 for Double-A New Hampshire and 2-0, 0.66 for Triple-A Buffalo before the Jays called him up in late June.

So, why fill Keller’s spot, at least for the time being, with a newcomer when Kansas City could have summoned from Omaha Austin Cox or Drew Parrish, the organization’s 28th best prospect per MLB Pipeline, or recalled Jonathan Heasley or Jackson Kowar from the Storm Chasers?

The Royals probably aren’t ready to use Cox just yet; he’s 4-7, 4.47 in 22 games and still needs some work. The same goes for Parrish, who’s 3-6 with a too-high 5.26 ERA after going 4-3, 2.13 at Double-A Northwest Arkansas.

Heasley, 1-7 with KC this year, was optioned back to Omaha Aug. 10 and isn’t eligible to be recalled (save for limited exceptions) until next week; in any event, he pitched for the Storm Chasers Tuesday, so he wouldn’t be ready to start tonight. And although Kowar pitched Sunday and might have been good to go against the Rays, the club probably wants him to work more at Triple-A before it gives him another shot at the majors.

Starting Castillo also affords the Royals the opportunity to give him an extended look before the season ends—at this point in the campaign, moving Keller back to the rotation doesn’t make much sense if they want to re-test him as a reliever. He spun a nifty 2.01 ERA in 21 games in that role for KC in 2018 before moving into the rotation and winning the first of his two club Pitcher of the Year awards.

There’s also a roster consideration: Castillo’s presence on the club’s 40-man roster means the Royals didn’t have to make room for him when they called him up. (In other moves today, KC DFA’d Joel Payamps, optioned Maikel Garcia to Omaha, and returned Hunter Dozier, who’d  been on the paternity list, to the active roster).

Castillo and the Royals need to make the best of this opportunity. As his good minor league numbers—45-18, 3.78 ERA in 109 games—and brief big league success reflect, Castillo is talented. And Kansas City needs rotation help.

Tonight’s first pitch at Tropicana Field is ser for 6:10 p.m. CDT.