Castillo will start Wednesday's game against the Yankees, Shannon Drayer of 710 ESPN Seattle reports.

EDGE Analysis

Castillo was dealt from the Reds to the Mariners on Friday in a blockbuster deal, and he'll face a tough matchup at Yankee Stadium during his first start with his new team. The right-hander recorded quality starts in his final five appearances with the Reds, posting a 1.59 ERA and 0.97 WHIP in 34 innings during that time.