SEATTLE -- Norm Charlton's injury was worse than the Seattle Mariners thought.

The left-handed reliever underwent shoulder surgery on Monday to repair a torn labrum as well as a torn rotator cuff.

Charlton's season-ending shoulder injury, announced by the team last week, at first was believed to be a torn rotator cuff.

"Norm had a torn rotator cuff and a torn labrum in the left shoulder," Dr. Larry Pedegana said in a statement released by the team. "I still anticipate one year for recovery."

The Mariners said Charlton injured his shoulder while working out in San Antonio, Texas, where he lives during the offseason, in early January.

Charlton, 39, helped the Mariners win an AL-record 116 games as the second left-hander in their bullpen last season. He will be 40 next Jan. 6.

Because of Charlton's age, his career is in jeopardy.

In his third stint with the Mariners, Charlton was 4-2 with a 3.02 ERA and one save in 44 appearances in 2001. He held left-handed hitters to a .169 (12-for-71) batting average.

Charlton made three appearances in the 2001 postseason and did not allow a run in 3 1-3 innings.

Charlton, who broke into the majors with Cincinnati in 1988, has a 51-54 record and a 3.61 ERA in 605 career games. He has 97 career saves, 67 with the Mariners.

In 1990, he was a member of the World Series champion Reds' bullpen. Rob Dibble, Randy Myers and Charlton earned the nickname "The Nasty Boys" for manager Lou Piniella, now ready to start his 10th season in Seattle.

With Charlton now finished for at least the season, the Mariners are down to one left-hander in their bullpen, Arthur Rhodes. They don't expect to sign a replacement because new bullpen addition Shigetoshi Hasegawa has been effective against left-handers.

With the likely signing of free agent right-hander James Baldwin to join the rotation, the Mariners are expected to keep Joel Pineiro in the bullpen and make left-hander John Halama their fifth starter this season.