PHILADELPHIA -- The end of Ben Sheets' 2008 season became a bit more official on Tuesday, when the Brewers' co-ace was left off Milwaukee's National League Division Series roster and revealed he has a torn muscle near his right elbow.

Sheets underwent another MRI scan on Monday in Milwaukee that revealed further tearing of the flexor mass, a muscle that helps stabilize the elbow. The tear was originally revealed in an MRI in late August or early September, after Sheets first felt pain in an Aug. 26 start against the Cardinals. For a time, he was able to pitch through the injury.

That changed on Sept. 17 at Wrigley Field, where Sheets exited a start and told reporters about his bum elbow. The right-hander attempted one more start, at Miller Park on Sept. 27, but he was forced out after allowing four runs in 2 1/3 innings.

Technically, Sheets would be eligible to make the NL Championship Series roster or the World Series roster if the Brewers advance that far. But even that is "doubtful," according to assistant general manager Gord Ash.

"I'm going to keep pushing like it's series-to-series," Sheets said. "But I don't know if that's realistic. I would say I'm out, most likely, unless I can hit. And I can't hit.

"We went aggressive at it," Sheets added. "I tried acupuncture, I tried massage. We tried everything. I tried it, and it didn't work."

When healthy, Sheets sure can pitch. He went 13-9 with a 3.09 ERA in 31 starts this season and also started the All-Star Game for the NL, the first Brewers pitcher in history to receive that honor.

Now, he may be at the end of his Brewers career. Sheets is a free agent after the season.

"I'm disappointed on a personal level," Sheets said, "but I feel like I've been a big part of why we're here. I'm pleased with that. I feel like I definitely helped us get to this point."

Sheets was talking specifically about this season, but he might have been talking in larger terms about the franchise's rise to prominence. He is the only player left from the start of the team's 106-loss 2002 season -- Bill Hall was a September callup that season -- and Sheets was considered a cornerstone of new general manager Doug Melvin's rebuilding effort that started in 2003.

In April 2005, Melvin gave Sheets a new four-year contract. The deal, which expires at the end of the month, paid Sheets $38.5 million and at the time was the richest in franchise history.

Over eight seasons with the Brewers, Sheets went 86-83 with a 3.72 ERA, tied with Larry Sorensen for fifth lowest in franchise history. Earlier this season he became the Brewers' all-time strikeout leader, and one more on Saturday made it 1,206 for his career.

Many fans will remember Sheets' injuries, and there were plenty. Over the years, the right-hander made six trips to the disabled list. But his teammates will remember the times he was on the mound.

"Ben Sheets is one of the main reasons we're in this situation," said Brewers catcher Jason Kendall. "He's been this franchise for a long time. Obviously, it's not my decision to make, but I wouldn't count that guy out just yet. He just needs rest."

That's true, according to Ash, who said Sheets' elbow will heal with time. With Game 1 of the NLDS set for Wednesday, the Brewers just don't have that luxury.

"It's a very easy heal -- it just takes time," Ash said.

Sheets would not say much about his own future. He'll be one of six inactive players in uniform on the bench for the NLDS. Where he goes from there is anybody's guess.

"Short-term, it's not good," Sheets said. "Long-term [estimate] would be fine. I was glad it wasn't something that it's short- and long-term. ... We starting pitchers are good cheerleaders."