He would let his anger linger hours after the game, often bringing it with him the next time he took the mound.
But Pelfrey -- the Mets' ace-in-training and the team's most consistent pitcher to this point in the season -- said that wouldn't be case after he allowed two separate leads to slip away and took a 5-3 loss at Yankee Stadium on Saturday.
"When I leave here today, the page will be turned," Pelfrey said. "That's one thing that in the past I would have carried with me and been upset and gone home and not talked to my wife, but that's not the case anymore. I'll leave it at the field and get ready for the next one."
The Mets will take a similar attitude into Sunday's Subway Series finale against CC Sabathia, whom they beat on May 23 at Citi Field. And why not? They've still won 12 of their past 14 games and are 7-1 overall on their current nine-game road trip, albeit with six of those wins coming against bottom-feeding Baltimore and Cleveland.
Win Sunday against Sabathia, and the Mets (39-29) will take the season series against the defending champion Yankees for just the third time in the 13-year history of interleague play.
Pelfrey and Phil Hughes took identical 9-1 records to the mound in Saturday's Subway Series game (the second time in major league history in which opposing starters had at least nine wins and a .900 winning percentage).
Neither starter was particularly effective. Hughes allowed five hits and three runs in seven innings, and Pelfrey (9-2, 2.69 ERA) couldn't keep pace. Pelfrey was staked to a 3-1 lead in the third with Jose Reyes' second homer of the game -- a two-run shot to right. But the big righty gave it right back in the bottom of the inning when he allowed a leadoff single to Brett Gardner and, two batters later, gave up a moon shot to Mark Teixeira on a 2-1 splitter that tied the score at 3-3.
"When you elevate off-speed pitches in this ballpark, you're going to pay for them," Mets manager Jerry Manuel said.
Pelfrey -- who beat Hughes head-to-head on May 22 -- hung another costly off-speed pitch in the bottom of the fourth inning, this time to Curtis Granderson. He drilled Pelfrey's hanging curveball about 20 rows back in the right-field bleachers to give the Yankees a 5-3 lead.
At that point, it was clear that neither ace-in-training was sharp, but Hughes got big outs when it counted, striking out Reyes with a man on first to end the fifth and inducing Jason Bay into an inning-ending double play with two on to end the sixth.
"Besides a few swings from Jose, [Hughes] shut us down," said David Wright, who had two strikeouts against the Yanks' starter and three on the afternoon.
Pelfrey, who came into Saturday having allowed just three homers in 86.2 innings, lost for the first time in eight starts. Even with Saturday's uneven performance, it's clear that he's a different pitcher in 2010, showing more confidence on the mound even when he struggles. Confidence has been an issue in the past for Pelfrey, who went 23-23 and displayed a maddening inconsistency in the past two seasons.
His first loss this year came on May 1 at Philadelphia, when he allowed six runs on eight hits in four innings. The 26-year-old says he turned the page quickly after that outing and is confident he can do it again Friday against Minnesota.
"It's the same thing, you know?" Pelfrey said. "I'll keep the routine the same thing, and I'll get ready for the next one. I'm not worried at all."