HOUSTON -- Jason Jennings' disappointing season came to a definitive halt on Tuesday, after an MRI revealed the right-hander has a tear in the flexor tendon in his elbow.

Jennings is done for the year and will have surgery on the elbow in the next 10 days to two weeks. The right-hander ends his season with a 2-9 record and a 6.45 ERA over 19 games (18 starts), falling far below expectations placed upon him when the Astros acquired him from the Rockies last winter.

"He's very disappointed," general manager Tim Purpura said. "He feels like he's let the organization down. It was an important trade and a big undertaking for us and the fact that he hasn't performed up to expectations, he's disappointed in that. But injuries are part of the game."

Purpura compared Jennings' elbow condition to Andy Pettitte's in 2004 and Billy Wagner's in 2000. Both underwent surgery to repair the flexor tendons, and both made full recoveries.

Jennings called the surgery option a "professional decision," without elaborating on whether he felt he could have continued to pitch through the injury.

"I had an MRI done today, I had an MRI in April," he said. "The one today was pretty much the same. I showed a little more deterioration of the flexor tendon. The MRI showed the ligament looked really good, which is great news, because that's a major surgery.

"This one, from what I understand, is a pretty easy fix. I'm hoping to get my surgery options, see where and when I want to do it and get it taken care of as soon as possible."

Jennings added that his elbow issues have been on his mind all season, but until very recently, he felt he could push through it.

"It's something I've stressed out about all season," he said. "But I'm not the type of guy to sit around and mope and make excuses and cry about my arm hurting. It's my job to go out and pitch. Some days you feel good and some days you don't.

"Days you don't feel good, you have to try to find a way to get outs. Unfortunately, I didn't do that often enough."

Jennings, who was acquired in a trade that sent center fielder Willy Taveras and pitchers Jason Hirsh and Taylor Buchholz to the Rockies, made two starts in April before going on the DL with tendinitis in his elbow. He returned in late May but was hardly the workhorse the Astros were looking for him to be as a No. 2 complement to Roy Oswalt.

Jennings stumbled through July, posting a 1-4 record and an 11.35 ERA over five starts. August wasn't much better. He was 0-2 with an 8.06 ERA over five games, including four starts.

The torn tendon in his elbow is likely a continuation of the damage that forced him to the disabled list for two months at the beginning of the season.

"One thing we talked about was the fact that pitchers try to compensate for injuries, and they sometimes get into bad habits," Purpura said. "That's some of what has happened here. That's the way Jason described it. He felt like more and more he was doing things that he was trying to get through a performance as opposed to dominating the competition. That's what's happened. He's gotten into bad habits to try to compensate."

Jennings concurred.

"Your arm hurts, you try to find a way to change your arm slot or change little things here and there to make it not hurt," he said. "That creates bad habits, and bad habits are hard to break. It's been a battle all year long. Trying to break those habits I created earlier in the year when I was hurt.

"It still hurts from time to time. The training staff's done a great job of making it tolerable and allowing me to pitch. It's something I wanted to try to battle through and do the best I can. It hasn't worked out. It's time to take care of it."

Jennings, 29, had never been on the disabled list for arm-related injuries through his six years with the Rockies. His only time off occurred in 2005, when he fractured his finger sliding into second base.

He threw at least 180 innings in four of his five full seasons in Colorado and recorded a career high last year with 212 innings pitched. He had experienced some elbow soreness in his final season with the Rockies, but the Astros were confident he was in good health when they pulled the trigger on the trade.

"He didn't miss any starts last year," Purpura said. "The [Rockies] general manager assured me he's fine. Our doctors talked to their doctors and were assured everything was fine. Beyond that, there's not a lot you can ask for."

Asked if he reviewed X-rays, Purpura responded, "I'm not going to get into what we saw or didn't see. The exchange of medical records was pretty complete."

Jennings, who is a free agent at the end of the season, hopes to be ready to pitch again by March 1.