OAKLAND -- A's right-hander Santiago Casilla exited Friday's appearance against the D-backs with a shoulder injury and is likely DL-bound. Oakland would go on to fall to the D-backs, 7-1.
Casilla has a right shoulder strain, per manager Bob Melvin, and there's a "good chance he'll be on the DL" come Saturday.
Casilla, who recorded two outs in the eighth inning before exiting with a trainer, suffered a similar injury in Spring Training and believes it to be minor.
"I felt my shoulder [was] a little bit tight when I started getting loose today," Casilla said through team interpreter Juan Dorado. "It was something that was bothering me in Spring Training, but I don't think it's something that will take long to heal or linger."
The 37-year-old veteran has a 3.32 ERA in 21 2/3 innings for the A's this season.