Lerew was struck in the ribs and right biceps by a line drive in the second inning, and a day later, the right-hander was pretty sore.
After Wednesday's game, manager Ned Yost said the Royals would have Lerew throw on Thursday in New York, and then be re-evaluated.
Although Lerew threw Wednesday and felt OK, Yost said before the game that it was unlikely the hurler would start Sunday against the Yankees.
"To be quite honest with you, I don't see it happening," Yost said. "He's pretty sore. We'll just have to wait and see. He's day-to-day."