Back then, the hard-throwing right-hander was short on each, as he often let his emotions get the best of him. But now, hardened by maturity and experience, Peavy certainly feels that he's made inroads in regard to poise.
"It's big for me to keep my emotions in check," Peavy said. "Back in the early days, it would have gotten out of hand. I've gotten better at slowing it down, waking around the mound. I have to channel it."
That's one of the things Peavy accomplished on Wednesday, as he channeled frustration, nervous energy and just about everything else on his mind into strikes, into big outs. And, in the end, into a 7-5 victory over the Mets before a crowd of 50,060 that wanted nothing more than for him to fold.
It never happened.
Peavy (14-5) worked out of a bases-loaded mess in the third inning, when he issued walks to Luis Castillo and David Wright.
Boiling point? It got to that point. Instead, credit a cerebral approach that helped Peavy get out of the jam.
Peavy got the red-hot Carlos Beltran looking at a nasty slider for the second out and then the other Carlos -- Carlos Delgado -- on a routine fly ball to left field to end the inning.
"That was a big at-bat," Peavy said of the strikeout of Beltran. "I had to step off and go through pitch selection in my head."
Peavy also made a big pitch during the fifth inning, when, after allowing a two-run double to Beltran, he left the Mets center fielder stranded on base when he again got Delgado to end the inning, this time on a pop-up to Kevin Kouzmanoff at third base.
That's not to paint Peavy as an absolute picture of coolness on the mound. He still talks to himself when things go wrong, although it looks more like he's scolding himself.
But the difference between the 21-year-old Peavy and the pitcher who tied Andy Benes for the franchise record for career strikeouts (1,036) with 11 on Wednesday was that reaching a boiling point didn't mean he boiled over.
"Even though he still shows his emotions, his in-game awareness is still solid," said Padres manager Bud Black. "He realizes what he needs to do to reel himself in."
The Padres (67-58) certainly needed Peavy to keep his wits about him on Wednesday, a day after they allowed the Mets (71-54) to rally for three runs over the final two innings for a 7-6 victory, a game that saw pitcher Chris Young leave with tightness in his lower back.
And with Young back in San Diego for a consultation with the team's medical staff to see what's troubling him, the Padres really needed their ace to pitch like, well, their staff ace.
Peavy didn't allow a hit until Jose Reyes singled to lead off the fifth inning. He walked five, though four of those came in the first three innings. All told, Peavy only allowed two hits in a 101-pitch outing.
"He's got some fire in him. He wants to win," Kouzmanoff said. "For him to get runners on and get out of it, that goes to show how good a pitcher he is. It's always good to have him on the mound."
And, of course, it's always nice to come up with some big hits, which is something that's often been absent in five of Peavy's starts this season, when he earned a no-decision even though he allowed two or fewer runs.
San Diego had five hits with runners in scoring positions, including an RBI double off Kouzmanoff's bat that staked the Padres to a 2-0 lead against Mets starter Brian Lawrence (1-1), the former Friar.
After getting another two-out knock -- an RBI single by Mike Cameron in the fifth inning -- the Padres essentially struck gold when, with two outs, Khalil Greene drilled a two-run single to left, followed by another RBI double by Kouzmanoff.
"Those two-out knocks, especially with runners in scoring position, are big," Kouzmanoff said. "You want to string some hits together when you're in those situations."
After going most of the game without bunching together many hits, the Mets found some success in doing just that in the ninth inning, scoring three runs and taking advantage of two Padres errors to make things interesting.
San Diego reliever Kevin Cameron allowed two hits to start the inning and committed an error before Black went to his bullpen for closer Trevor Hoffman, who got his 32nd save of the season, despite an error that allowed a run to score.
Hoffman got Delgado to chase one of his nasty changeups in the dirt the end the game.
Afterward, Hoffman sounded more like a proud father than a closer as he talked about the way the Padres came back from such a disheartening loss and the loss of Young to win on Wednesday.
"You're going to have your losses," Hoffman said. "But it shows there's no quit in these guys."
Corey Brock is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.