Updated

Cincinnati's Johnny Cueto left his Game 1 start against the San Francisco Giants on Saturday night in the first inning because of back spasms.

The Red said he is day to day. The right-hander threw a second strike to No. 2 hitter Marco Scutaro and walked off the mound in obvious pain. A trainer and manager Dusty Baker rushed out to check on him, and the 19-game winner came out moments later.

He retired leadoff man Angel Pagan on a strikeout. During the at-bat, Pagan stepped out of the batter's box and was granted time. Cueto apparently didn't see it and continued his motion.

He threw eight pitches and six strikes for the earliest postseason exit by a starter since Atlanta's John Thomson lasted one-third of an inning in Game 3 of a 2004 NL division series against Houston. Thomson came out with a sore muscle in his left side.