Peavy's optimism came after he allowed two home runs in his final spring start as the Chicago White Sox lost to Triple-A affiliate Charlotte, 4-3, on Thursday night.
Peavy gave up three runs on four hits with seven strikeouts and no walks in four innings. Peavy struck out six through three scoreless innings before surrendering home runs to Stefan Gartrell and Josh Kroeger on cut fastballs. He left after throwing 68 pitches.
"I feel real good. I do," said Peavy, scheduled to start Wednesday against Cleveland. "Almost everything is working. Just the cutter, just trying to figure that out during the last inning."
Mark Kotsay and Carlos Quentin homered for Chicago, which played its regulars four innings before finishing the game with many players from Class A Winston-Salem.
Jeff Marquez allowed two runs on five hits in five innings to get the win for the Knights.
Peavy, limited to 16 starts last season with San Diego and Chicago because of a right ankle injury, was tagged for seven runs on 10 hits while throwing mostly fastballs against Kansas City on March 22. Five days later, he gave up seven runs on 12 hits in a Minor League game when he also relied on fastballs.
"He's just so smart. He wanted to work on his fastball and not see the opposite team see his pitches. I don't think too many pitchers do that," White Sox manager Ozzie Guillen said. "Couple hours later, I saw genius people talking about how bad Jake Peavy was."
Peavy laughed at the concerns.
"I think it's funny that people get worried about Spring Training," Peavy said. "Guys just go about their business differently. They work on stuff."
Peavy was struggling with his cutter, so he decided to keeping throwing it after allowing a single to Jordan Danks to lead off the fourth. Gartrell and Kroeger then hit consecutive homers off that pitch.
"Fastball, breaking ball, changeups were very good. Cutter, I obviously gave up three hits that inning," he said. "Tried to stay with it, trying to get better. Got a couple bullpen [sessions] in between this next start. We're going to have to work on that to straighten it out. I'm going to need it against those lefties in the Cleveland lineup."
Kotsay's second home run of the spring off Marquez put Chicago ahead, 1-0, in the second inning. Quentin's fifth homer in the fourth made it 2-0.
A crowd of more than 10,000 watched the White Sox first game against Charlotte here since 1999.
"It was a little different feel than a Spring Training feel, a little more adrenaline," Peavy said. "So that's always fun."
The only White Sox regulars given the day off were first baseman Paul Konerko and catcher A.J. Pierzynski, who caught nine innings a day earlier in Arizona.
Konerko had a cortisone shot in his left hand to treat a lingering thumb injury, but a team spokesman said he'll play Friday in Atlanta.
Notes: Light-hitting shortstop Omar Vizquel struck out in his only at-bat as the White Sox DH. "He's the oldest man on the team," explained Guillen, smiling. "We fly six hours. I don't want to hurt him." But Guillen said he could use Vizquel or Juan Pierre occasionally at DH this season. ... Charlotte catcher Tyler Flowers threw out Pierre trying to steal second in the second inning. ... Guillen's advice to first baseman Dayan Viciedo, who did not make the 25-man roster: "Buy a house here in Charlotte, or put yourself together and hurry up and come to the big leagues." Viciedo dropped a throw to first in the second.