NEW YORK -- The Mets just lost a bit of their rotation depth.

Right-hander Boof Bonser will undergo Tommy John surgery next week, the Mets announced Thursday. Bonser, who competed for a starting job this spring, left his last start with Triple-A Buffalo after four innings due to right forearm discomfort.

Over a four-year big league career with the Twins, Red Sox and A's, Bonser is 19-25 with a 5.18 ERA. The Mets signed him to a Minor League deal this past offseason with an invitation to Spring Training. Along with Dillon Gee and Pat Misch, he had been one of the team's primary insurance options at Buffalo.

Young throws in bullpen, will start Sunday

NEW YORK -- In what he called a "normal progression" between starts, Chris Young threw his regular bullpen session Thursday morning, easing worries about his ailing right arm.

"I wouldn't have gotten on the mound if I had felt something," Young said.

Originally scheduled to start Friday's game in Atlanta, Young was pushed back two days in the rotation after complaining of right biceps tendinitis. But despite Young's history of shoulder problems, neither he nor the team considers the issue serious.

"He's still a go for Sunday," Mets manager Terry Collins said Thursday morning. "As a matter of fact, he said he felt a lot better today."

Beltran yet to play day game after night game

NEW YORK -- This weekend's series in Atlanta presents a new challenge for Carlos Beltran, who has yet to start a day game after a night game this season. Following a night game Friday, the Mets will play matinees Saturday and Sunday at Turner Field.

"Hopefully we can get him in there," manager Terry Collins said. "But I certainly will check with him each day."

Beltran, who sat out most of Spring Training with left knee tendinitis, was not in the lineup for the first game of Thursday's doubleheader against the Rockies. He was scheduled to play Game 2 instead in an effort to give his knees more time to rest.

Buchholz not rattled by facing Rockies

NEW YORK -- Taylor Buchholz had no qualms Wednesday evening about facing the Rockies, his employer for three seasons before joining the Mets. It did not feel strange. It was not uncomfortable.

"But it was nice to get Tulo," Buchholz said of whiffing Rockies slugger Troy Tulowitzki. "I'll take that."

Striking out batters is something Buchholz has been doing with regularity this season, fanning nine over his first 6 2/3 innings. He has been perhaps the Mets' most consistent bullpen arm, leading manager Terry Collins to consider using him in eighth-inning setup situations.

In 108 career games as a reliever entering this season, Buchholz had struck out an average of 6.4 batters per nine innings. But he has whiffed opposing batters at nearly twice that rate so far this year, relying more heavily on his curveball and changeup. In a departure from years past, he is throwing those two pitches more than half the time.

"I've been able to get ahead with my offspeed pitches," Buchholz said, "and I have my put-away curveball working pretty well right now."

Worth noting

Despite D.J. Carrasco's inning of relief in Wednesday's game, the Mets still plan to have Carrasco start Friday's series opener in Atlanta. "He'll be ready," manager Terry Collins said. "I think he can get us through the fifth or sixth, then we'll pick it up from there." ... Second baseman Brad Emaus, who grew up 30 minutes south of Atlanta, expects to have more than 20 family and friends in attendance for this weekend's games at Turner Field. "It'll be nice," Emaus said. "It'll be fun. I'll have a good time."