Atlanta (92-66) has won each of Medlen's last 22 starts dating to the 2010 season. A Braves victory Sunday would set a major league record of 23 consecutive wins by a team in one pitcher's starts.
Medlen (9-1, 1.64 ERA), who pitched the first four months of the season out of the bullpen, is 14-0 with a 2.57 ERA in 27 starts since losing his first two career starts in May 2009. The Braves have gone 25-2 in those contests.
He has allowed 10 runs and struck out 80 over 77 2-3 innings while going 8-0 in 11 starts since joining the rotation July 30.
"It's already surreal," Medlen told the Braves' official website. "But obviously, I don't plan on it ending (Sunday), and hopefully keep it going."
The streak nearly came to an end Tuesday, when Medlen allowed three runs on two homers in seven innings. The Braves trailed 3-2 in the bottom of the ninth before Freddie Freeman hit a two-run homer to put Atlanta into the playoffs.
Medlen is 2-0 with a 2.19 ERA in two starts versus New York this season -- both at Citi Field.
He'll try to help the Braves build some momentum heading into the postseason as they look to win their final regular-season home series after a 2-0 victory over New York (73-85) on Saturday. Mike Minor threw 6 1-3 innings and Martin Prado went 2 for 4 with an RBI as Atlanta won for the 11th time in 14 games.
After going 0 for 4 on Friday night when he was honored at Turner Field, Chipper Jones again went hitless in four at-bats Saturday. With the postseason and retirement looming, Jones is 0 for 13 in his last four games.
It's uncertain if teammate Michael Bourn will be in the lineup after he missed a sixth straight game Saturday with a sprained left thumb. Bourn is 7 for 17 with five RBIs in his last four games against New York at Turner Field.
Though the Mets will miss the playoffs for a sixth straight season, David Wright is batting .346 (9 for 26) with nine RBIs in his last seven contests. He had one of five hits Saturday for New York, which lost for just the second time in nine games.
New York's Jenrry Mejia (1-1, 4.91) takes the mound looking to build on his first major league victory. In his fifth career start and second this season, the right-hander allowed four hits in five scoreless innings of a 6-2 win over Pittsburgh on Monday.
"I hope he realizes his stuff's good enough if he's around the plate," manager Terry Collins said about Mejia, who underwent reconstructive elbow surgery in May 2011 and will make his fifth appearance this season. "I thought it was a huge step for him."
Mejia allowed a homer to Dan Uggla while pitching two innings out of the bullpen Sept. 7.
Copyright 2012 by The Associated Press
This story is from ESPN.com's automated news wire. Wire index