Naylor left Tuesday's game versus the Royals with an acute back spasm, Joe Noga of The Cleveland Plain Dealer reports.
Naylor went 1-for-4 but exited in the eighth inning, with Jhonkensy Noel replacing him as a pinch runner and staying in the game at first base. Noel could see time at first base if Naylor is unable to play in Wednesday's series finale. Naylor has mostly avoided injuries this year, missing time with general soreness in late July.