NEW YORK -- Mets left-hander Mike Hampton threw for 12 minutes in the bullpen Friday and his fractured rib felt good enough for him to return to the New York rotation Sunday.

Hampton threw all of his pitches in Friday's 60-pitch side session and was cleared to start the final game of the weekend series against the Arizona Diamondbacks, New York's closest pursuer in the wild-card race.

"I was pleased with the way the bullpen session went. It was definitely a positive," Hampton said.

Hampton was forced to leave in the third inning during his last start on Aug. 17 against Colorado after he was injured while batting. It is not believed that Hampton will hurt the rib worse by returning. The only concern was whether his mechanics would be altered to compensate for the pain.

"I won't do that," Hampton said. "I said to myself today, 'Just go out there and let it go.' And I was able to do that."

Pat Mahomes took his place in the rotation on Tuesday and allowed 10 runs on seven hits in four innings in a 16-1 loss to the Padres. Outfielder Derek Bell pitched the eighth inning for the Mets.

Hampton, who can be a free agent following the season, grounded out for the final out of the third against the Rockies and opened with fourth by walking Todd Helton on a 3-1 count.

Hampton threw a ball to Jeffrey Hammonds, and Mets pitching coach Dave Wallace and the team's training staff went to the mound. Hampton then left the game.

"The less amount of home-run swings I take will probably be better for me," Hampton said. "Once I'm in a game though, I don't do a whole lot of thinking."

The small stress fracture, which dates to Hampton's high-school football days, was revealed by X-rays.