Yates (undisclosed) left Friday's game with a trainer after throwing just six pitches, Kevin Acee of The San Diego Union-Tribune reports.
Yates had dealt with soreness over the past week but entered in the eighth inning of Friday's game against the Diamondbacks. He struck out one batter with six pitches, but he then exited the game with a trainer due to an apparent injury. The nature and severity of the issue are unclear, but it's certainly a discouraging development for the right-hander since he missed time prior to Friday.