OAKLAND -- Josh Donaldson is dealing with back stiffness and was out of the A's lineup for a second straight day on Thursday.
"That was the reason he wasn't in there yesterday," manager Bob Melvin said before Thursday's series opener against the Blue Jays. "We'll give him another day here, see how he feels tomorrow."
Donaldson took regular batting practice on Thursday, but did not field any ground balls. Melvin wanted to see how the third baseman felt after swinging the bat to determine whether he might be available off the bench.
Thursday marked just the fifth game this season that Donaldson has not started. He has 18 home runs and 61 RBIs and looks poised to start his first All-Star Game, though his average has dipped from .284 to .245 since June 1.
Aaron Leibowitz is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.