NEW YORK -- CC Sabathia does not believe that he has thrown the final pitch of his Major League career, but if the veteran left-hander is to return to the mound, his Yankees teammates will need to advance past the Twins in the American League Division Series.

Sabathia was not included on the Yankees’ 25-man roster for the ALDS when it was announced on Friday morning. Manager Aaron Boone said on Thursday that the 39-year-old’s left shoulder is “not bouncing back as well as we would have hoped” following a recent cortisone injection.

“It's tough being here and not being able to participate in the playoffs,” Sabathia said. “I didn't want to put the team in jeopardy. I want the best opportunity for this team to win a championship. I feel like we have a good opportunity. I didn't want to be selfish and go out there hurt and put the team in a bad spot.”

Sabathia made the first regular-season relief appearance of his career on Sept. 24 against the Rays at Tropicana Field, striking out two in a scoreless fourth inning. Sabathia said that he felt fine after that outing, but his aching shoulder prevented him from pitching, as originally scheduled, in the season-ending series against the Rangers at Arlington.

The hurler said that the shoulder issue has been something that he has been dealing with for “the past couple of months,” in addition to a degenerative right knee condition that Sabathia has been battling for several years.

“It's something that I never dealt with, having arm problems,” Sabathia said. “I’m trying to work through it, do things in the training room to try to get back out there and play some catch and see how it feels.”

Sabathia threw from the Yankee Stadium mound in a simulated game on Tuesday afternoon, but to Boone and the coaching staff, that outing did not inspire confidence that Sabathia would be ready to come out of the bullpen during the ALDS.

“He’s just not quite where it needs to be to be in the kind of role we're going to ask him to be in, where he's potentially getting up on the spot and then maybe having to get up later in the game,” Boone said.

Boone said that he had been envisioning Sabathia in shorter relief stints, perhaps against a left-handed batter or a switch-hitter. Boone declined to say if the Yankees plan to have 12 or 13 pitchers on the roster, but Sabathia’s situation seems to increase the likelihood that the Yankees will carry a situational left-hander such as Tyler Lyons or Stephen Tarpley.

“I wasn't looking at [Sabathia] so much as a bulk guy, because I thought there were a couple of matchups that we liked that we thought he would be good in,” Boone said.

Sabathia said that he will continue to prepare in hopes of being added for the next rounds of the postseason, should the Yanks advance.

“I do feel like the longer we go, it's a better chance that I can get back out there,” Sabathia said.

Sabathia completed the regular season with a 5-8 record and 4.95 ERA, a farewell campaign that saw him log both his 3,000th career strikeout and his 250th career victory. Sabathia’s Hall of Fame candidacy will feature a 251-161 record, a 3.74 ERA and 3,093 strikeouts. He is 16th all-time in strikeouts.

“It's been fun; it's been a good year,” Sabathia said. “Everything I had to do to stay on the field with cortisone shots and different things like that, it's tough, but to be here with these guys and be in a position to, hopefully, win a championship is why I came back.”