"Oh yeah. It's just one of those things where you try to get some rest," Peavy said before the Padres played the finale of a three-game series against the Philadelphia Phillies.
Peavy came in for treatment but went home about two hours before game time.
He said he was taking "quite a bit" of medication.
Peavy, the 2007 NL Cy Young Award winner, allowed four runs on three hits, two walks and a sacrifice fly in the first inning of the Padres' 10-5 loss to the Phillies on Tuesday night.
"I felt like it looked," he said. "I felt like I could get going with some adrenaline, and the trainers and doctors did everything they could do, but I just didn't have that much to go on."
His previous shortest start was two innings at Arizona on Aug. 25, 2003, during his first full big league season.
The Padres are off Thursday before opening a four-game series against Arizona. Manager Bud Black said Peavy will start either Sunday or Monday, depending on his health.
"Hopefully as each day goes on, his illness will creep away," Black said.
Outfielder Scott Hairston was placed on the 15-day disabled list Wednesday. He strained his left biceps swinging during his second at-bat on Tuesday night and left the game after flying out.
"I've never had an injury like this before, so I don't know how my body's going to react," Hairston said.
Hairston has a team-high .327 batting average, with eight home runs and 23 RBIs. He homered in three straight games prior to Tuesday night.
"It's always a bummer to go on the DL. But, it's happened and right now my focus is on getting healthy and doing all I can to get it right," Hairston said.
"He's been a big part of our offense -- his batting average, his on-base percentage, he's hit some big homers," Black said. "We'll have to get contributions from other guys to pick up what Scotty was providing for us."
The Padres recalled Will Venable from Triple-A Portland and he started in left field on Wednesday night.
Venable played in 53 games for the Beavers, hitting .260 with 12 homers and 30 RBIs.