Bay had an MRI exam Monday that revealed no structural damage.
He was lifted in the fourth inning of Saturday night's game against
the Cubs because of knee pain.
"It's nothing that should end my season," Bay said. "I'll
take it easy for a few days and try to get back in there."
Bay had arthroscopic surgery on his left knee after last season.
He is going through the worst of his four full seasons with
Pittsburgh, hitting .253 with 20 homers and 82 RBIs. The 2006 NL
All-Star starter has been bothered by recurring knee discomfort,
but he has not cited that as a reason for his below-average season.
Pirates outfielder Xavier Nady remained out of the lineup again
Monday because of headaches related to being struck in the head by
a pitch Sept. 3. Nady won't be cleared to play until the headaches