The 42-year-old left-hander says he felt tightness while throwing a one-ball, one-strike pitch to Nationals outfielder Wily Mo Pena with two on and no outs in the bottom of the first inning.

He was unable to loosen it while walking behind the mound after the play and was replaced by reliever Jeff Bennett.

"As soon as I landed, I felt it," Glavine said on the Braves' Web site late Sunday. "I don't know if I'd describe it as having popped or anything, but it definitely grabbed, or it kind of rolled on me. So I knew right away that it didn't feel right. I tried to walk around and stretch it out. It seemed like the more I tried to stretch it out, (the more) it hurt."

Glavine never has been placed on the disabled list through 642 major league starts.