Astros reliever Brandon Lyon underwent his scheduled surgery Thursday in Pensacola, Fla., as Dr. James Andrews repaired a detachment of his right biceps tendon and repaired his right labrum, which had been a lingering injury.

Lyon is expected to miss the rest of the season and will start range-of-motion exercises in two weeks.

The procedure had been open-ended, as Andrews and Astros team physician Dr. David Lintner, who was present at the surgery, knew the biceps would have to be fixed but were set to explore the labrum and rotator cuff.

Lyon finished his season with an ERA of 11.48 and four saves in eight chances around two stints on the disabled list. He has one more full season on a three-year, $15 million contract signed before the 2010 season.

No rush for Castro

At anything close to this pace, he’s not going to be the difference between a playoff run and an October at home, so there’s not that pressure on catcher Jason Castro.

Castro made it clear he’s going to try to be back in September, as general manager Ed Wade said Wednesday was a possibility.

“Obviously I want to play,” Castro said. “When that’s going to be, I think right now it’s too early to tell just because we’re just starting to get into the more serious stuff.”

That has involved swinging off a tee in addition to his running. Castro has also begun agility drills including jumping and side-to-side motion.

The would-be major league sophomore was diagnosed with a torn anterior cruciate ligament March 4 after taking a bad step to avoid a tag in a spring training game. He said there have been no setbacks in what was estimated as a six-month recovery and he is Florida-bound in mid-July to continue there.

“If I were to be able to come back and play this year at all, I would be thrilled with that,” Castro said. “That’s definitely my goal to push myself as hard as I can and have that possibility of coming back. But at the same time, I’m realistic as to the progression of the rehab.”

With his season being abbreviated if it even starts at all, Castro might seek options in winter ball.

Carpenter debuts

Astros reliever David Carpenter made his major league debut Thursday, working the eighth inning of a victory over the Rangers.

A scoreless eighth inning in a 7-0 victory.

Carpenter, a converted catcher, had a 19-inning scoreless streak at Class AAA Oklahoma City when he got the call to the major leagues. Among those in the crowd of 25,938 who witnessed his three-up, three-down outing were his parents.

“I was trying not to look at anybody else,” Carpenter said. “I was trying to pull the bill of my hat down as far as I could, just concentrate on looking at (catcher J.R. Towles) glove.”

Carpenter, 25, struck out the first hitter he faced, Craig Gentry. What would an EKG of Carpenter look like while he was on the mound?

“It would have been all over the place,” Carpenter said. I’m just really happy I was able to get a chance to go out there and be part of a win.”

Keppinger out

Second baseman Jeff Keppinger was scratched from the lineup roughly 90 minutes before the game because he was experiencing nausea. Angel Sanchez took his spot at second base and in the No. 2 hole in the order.

Catching up

Catcher J.R. Towles returned to action behind the plate six days after taking a foul ball to the mask and needing 11 stitches to repair the gash.

Catcher Humberto Quintero will start his rehab assignment today with Class AAA Oklahoma City. He is targeting a return for the Pirates series coming after the All-Star break.