Mark McGwire, the former single-season home run king, told ESPN's Rich Eisen on Sunday that he is "worn out" and will retire from baseball.

	McGwire

McGwire strongly hinted of retiring several times this year, when he batted just .187 with 29 home runs as he was slowed by a bum right knee.

McGwire had agreed to a $30 million, two-year contract extension in spring training but never signed the deal.

"After considerable discussion with those closest to me, I have decided not to sign the extension, as I am unable to perform at a level equal to the salary the organization would be paying me," McGwire said in a statement. "I believe I owe it to the Cardinals and the fans of St. Louis to step aside, so a talented free agent can be brought in as the final piece of what I expect can be a World Championship-caliber team."

Cards taken off guard

The announcement took the Cardinals by surprise. Manager Tony La Russa said he and McGwire have spoken often since the end of the season and the slugger hadn't told him about the decision. "I would believe he would have told the Cardinals first," La Russa said. "The guy is a first-class guy. I find it hard to believe he wouldn't call the owners or (general manager Walt) Jocketty first." Jocketty, when he heard that ESPN had received a fax from McGwire and his representative that he was retiring, told the St. Louis Post-Dispatch, angrily on Sunday night, "I know nothing about this. I'm a little upset about this. It would shock me that he would tell ESPN before he would tell Tony and myself." La Russa said he had tried to speak to McGwire on Thursday but that McGwire was unavailable. McGwire is out of the country on vacation. "I'm skeptical enough that until I hear this officially, I don't take the fax as gospel," La Russa said. "But he's warned us so much to make plans. If I had to guess, I would guess that it is real. But there's no harm in waiting until it becomes official, so I'm going to wait till it becomes official. Or at least till he tells it to somebody besides ESPN." La Russa, who had left two messages for McGwire, said, "He'll call me when the time is right. My guess is that when he explains it, we'll understand it. He has given all of us enough warning so that we were making plans without him." A Cardinals spokesman said Monday that the team still has not heard from McGwire.

McGwire captured the nation's imagination in 1998 while hitting 70 homers to break Roger Maris' 37-year-old record. It was a short-lived mark as Barry Bonds hit 73 homers this season.

McGwire has 583 career home runs, fifth on the career list, and finished his career 17 shy of becoming the fourth player to hit 600 homers.

"This is something that will impact everybody, said Cardinals third baseman Albert Pujols, who was voted the National League Rookie of the Year on Monday.

"It shocked me when I heard it last night," Pujols said. "But it's something I'm sure the Cardinals will take care of. We've got a good general manager in Walt Jocketty and I'm sure he'll take care of it."

McGwire, who began his career with Oakland in 1986, won the World Series with the A's in 1989 and reached the postseason six times.

"For years I have said my motivation for playing wasn't for fame and fortune, but rather the love of competing," McGwire said in the statement. "Baseball is a team sport and I have been lucky enough to contribute to the success of some great teams."

He labored through the 2000 season with a bad right knee, missing virtually all of the second half. He had surgery to correct patella tendinitis but again struggled with the knee this season.

While no formal announcement is planned, Cardinals spokesman Brian Bartow said Monday that the team has received a copy of McGwire's statement expressing his desire to retire.

"All indications point to the fact that what we received from Mark is accurate," Bartow said.

Bartow added that general manager Walt Jocketty is trying to contact McGwire, who is vacationing in Mexico.

McGwire's retirement comes amid reports that the massive slugger is wooing prized free agent Jason Giambi of Oakland as his possible replacement. With payroll concerns, the Cardinals could not possibly afford both McGwire and Giambi.

McGwire always will be remembered for his titanic blasts that dotted highlight shows. Among the more memorable were an upper-deck blast at the Kingdome off Randy Johnson, a shot off Yankees closer Mariano Rivera into the black seats at Yankee Stadium and a game-winning homer in Game 3 of the 1988 World Series.

But McGwire's most special homers came in 1998 as he closed in on Maris' single-season record. With a national television audience tagging along, McGwire not only broke the record but shattered it.

Chicago Cubs superstar Sammy Sosa hit 66 homers in 1998 and became close friends with McGwire during their epic chase.

"He must have a good reason for his decision," Sosa said. "He's a great person and a great ambassador for the game of baseball. I am going to miss him and baseball will miss him.

"The way he declined the money from the Cardinals so that they can bring someone else in to replace him ... that's a class act."

McGwire homered in the first four games in 1998, hit the longest homer in Busch Stadium history on May 16 and reached the upper deck at the Astrodome on June 18.

Then on Sept. 7, in one of the game's magical moments, McGwire lined a pitch from Mike Morgan inside the left-field pole for the record-tying homer. The next night, McGwire made history with a line drive over the left-field wall off Steve Trachsel for the record-setter.

The homer was so momentous that national broadcast networks cut into prime time programming to show the homer and the ensuing celebration, which took place with the Maris family on hand. He would go on to hit 70 that season but the record stood just three years.

During his magical season, McGwire was subjected to criticism for his use of nutritional supplements. In the wake of many injury-plagued campaigns, McGwire has found himself defending his physique and training methods.

McGwire also said he would retire if a labor dispute between baseball and the Players Association resulted in another work stoppage. The current collective bargaining agreement expired last week.

Information from ESPN's Rich Eisen, The Associated Press and SportsTicker was used in this report.