A dye MRI taken Wednesday afternoon revealed that Felciano has a torn capsule in his left shoulder, and he is leaning toward arthroscopic surgery, he told reporters before Thursday night's game against the Baltimore Orioles. Before that he will get a second opinion from renowned physician Dr. James Andrews on Monday.
General manager Brian Cashman characterized the injury as "significant."
"It is a Chien-Ming Wang-like issue," Cashman said. "And he is still trying to come back with Washington. Some people can come back, but the odds are a lot more difficult."
While with the Yankees, Wang had shoulder surgery in July 2009, and the former 19-game winner still hasn't pitched in the majors.
Surgery appears to be the likely route for Feliciano.
"Most likely that opinion will hold up, unfortunately," Cashman said, "because this is not a close call, it appears to be very obvious."
He added: "Capsular tears are very serious. In all likelihood he's looking at a significant surgery."
If Feliciano does have to undergo surgery, which would take place some time next week, he would have to undergo a year of rehab. He said he would likely be ready for the start of spring training in mid-February.
"It's really disappointing," said Feliciano, who suffered the injury during his fourth appearance in spring training. "I love to pitch and I want to be a guy that pitches every day like I've been doing for the past three or four years. And now to be shut down for maybe a year, I don't know how I'm gonna handle it. It's gonna be hard."
Feliciano said that if Andrews tells him he won't need surgery, he could get a platelet-rich plasma injection in his shoulder, wait a month or two and try to throw again. However, that seems unlikely.
"He's a warrior and a competitor and now he can't compete because of this injury he sustained when he was a member of the New York Yankees in spring training," Cashman said.
Feliciano tried to pitch through the pain in spring training.
"I kept pitching because I thought it was gonna go away," Feliciano said. "My first three outings were fine. I came into spring training ready to go and 100 percent."
Feliciano pitched a scoreless inning while striking out the side on Mar. 9 against the Pittsburgh Pirates. But during the appearance, Feliciano knew something was wrong.
"I threw long toss with Rafael Soriano. I was fine," Feliciano said. "Then I threw my short toss and my bullpen and I was fine. Then after I got my first strikeout, I gave up a bloop single to right and then I struck two guys out. But the last two outs, I knew I wasn't me. It was weird. I'd never felt anything like that. I kept pitching, but the next day it was bad."
The Yankees signed Feliciano this offseason to an $8 million, two-year deal. They wanted him to complement Boone Logan as a lefty specialist and compete with Joba Chamberlain as the eighth-inning guy.
Yankees manager Joe Girardi said "the bullpen is what it is. We believe we have right-handers that are capable of getting lefties out."
"Boone Logan stepped up for us last year. He's going to have to do it again," he added.
On Tuesday, Feliciano played catch for the first time in a couple of weeks and didn't come through it well.
Afterward, he went to see team doctors who ordered an MRI. The results came back on Wednesday and Girardi revealed that Feliciano has a "shoulder issue."
The Yankees weren't blindsided by Feliciano's extensive use with the Mets, where he led the league with 266 appearances over the past three years. With Feliciano sidelined, Cashman said that the Mets "abused" Feliciano.
Feliciano disagreed with that but was hurt that Mets pitching coach Dan Warthen said one of the reasons the Mets didn't bring the pitcher back was because of concern over innings pitched. Feliciano had vowed he would be back by next month's Subway Series.
Cashman also took several minutes to use the Thursday news conference as a "forum" to defend his record against accusations in the media that he was a hypocrite for attacking the Mets on their usage of Feliciano when former reliever Scott Proctor made 83 appearances for the Yankees in 2006 and again in a season split with New York and the Dodgers in '07.
"If you want to get [former manager] Joe Torre on the phone you'll know I'm not a hypocrite," Cashman said. "I dealt with our pitching coach, with our manager. We have new people here that utilize people in a certain way. These guys aren't [infinite] assets out there. There's a very limited group of people capable on a consistent basis of performing at the major league level at a high level of success."
Mike Mazzeo is a regular contributor to ESPN NewYork.com. Information from ESPN NewYork.com's Andrew Marchand and Ian Begley and The Associated Press contributed to this report.