He threw fastballs without discomfort, but his thumbnail hurt on breaking balls.
"He's only a little tender in the nail area, it's surprising," said manager Don Mattingly. "He's not a DL guy, we think this would be really short term."
Guerrier was hit on the bare hand by a liner from the Padres' Yasmani Grandal, then threw him out at first to end the inning.
Ken Gurnick is a reporter for MLB.com. Austin Laymance is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.