Andy Pettitte to retire Friday

NEW YORK -- The Core Four is now down to We Three.

As many expected since the New York Yankees' 2010 season ended in disappointment in Texas, Andy Pettitte will officially announce his retirement at a news conference at Yankee Stadium at 10:30 a.m. ET on Friday.

Pettitte's intentions, first reported by 1050 ESPN Radio's Michael Kay, were confirmed by the Yankees in announcing the news conference.

Pettitte phoned Yankees owner Hal Steinbrenner to inform him of his decision, sources told ESPN The Magazine's Buster Olney.

"We thank Andy, his wife, Laura, and their family for their many contributions to this organization," managing partners Hank and Hal Steinbrenner said in a statement. "We hope the Pettitte family remains a part of the Yankees family for years to come, and we wish them nothing but the best moving forward."

Pettitte, who will turn 39 on June 15, has wrestled with thoughts of retirement for the past several seasons. But never had he seemed more serious about the imminent end of his career than last season, when he spoke several times about his desire to spend more time at home in Deer Park, Texas, with his wife and their four school-age children.

Pettitte's upcoming role as the star prosecution witness in the perjury trial of Roger Clemens, his former teammate and friend, may have also played a factor in his decision.

But until Thursday, some Yankees officials were holding out hope that as in years past, Pettitte would reconsider as spring training drew closer, a hope that became more urgent when the Yankees failed to sign Cliff Lee as a free agent this winter.

General manager Brian Cashman, however, had remained consistent in his belief that Pettitte would not be a part of the Yankees' starting rotation this season.

"Andy's not in play," the GM said repeatedly this winter. "Unless he tells me otherwise, I'm proceeding as if he won't be with us next year."

Pettitte compiled a 240-138 record and 3.88 ERA in 13 seasons with the Yankees and three with the Houston Astros. He is a three-time All Star, a two-time 20-game winner and a member of five Yankees world championship teams. He appeared in two other World Series with the Yankees as well and another with the Astros. He's won more games, 19, than any pitcher in postseason history.

Along with Derek Jeter, Mariano Rivera and Jorge Posada, he was among the last remaining members of the Yankees teams that won four championships in five seasons between 1996 and 2000.

"I'm really sad that Andy is going to retire," said Posada. "He was so much more than a teammate to me -- he was one of my closest friends. I admire everything that he has accomplished as a Yankee, but Andy was someone who always put the team first. I'm going to miss him deeply."

Pettitte got off to the best start of his career in 2010, going 11-2 with a 2.38 ERA before a groin strain suffered on July 18 robbed him of two months of the season. He finished up 11-3 with a 3.28 ERA and went 1-1 in the postseason, beating the Minnesota Twins in Game 2 of the ALDS and losing Game 3 of the ALCS to the Rangers and Lee despite allowing just two runs in seven innings.

Pettitte's decision to retire leaves the Yankees treacherously thin in the starting rotation, with CC Sabathia, Phil Hughes and A.J. Burnett the only experienced returning starters on the staff.

Ivan Nova, who made a handful of starts as a rookie last season, is expected to fill the No. 4 spot and a collection of retreads (Sergio Mitre plus new acquisitions Bartolo Colon and Freddy Garcia) will compete for the No. 5 spot in spring training unless Cashman can add another experienced starter.

Cashman did not immediately return a phone call seeking comment.

"Since I've been retired, I'm always asked, 'Who would you have pitch a World Series Game 7?' And I always say, 'Andy Pettitte.' When people ask why, I tell them it was because he was so prepared for every start," said former teammate Tino Martinez. "When the time comes for a big game, you want a guy who's going to give you seven strong innings. And that's what he did time and time again."

Wallace Matthews covers the Yankees for ESPNNewYork.com.