CHARLOTTE, N.C. — Mike Rucker, the second-leading tackler in Carolina Panthers history and one of the franchise's most recognizable players, is retiring after nine seasons.

Rucker will make the announcement at an afternoon news conference at Bank of America Stadium, a team official said today.

The move comes 10 weeks after Rucker decided he'd try to play for at least one more season. But the 33-year-old Rucker recently began having second thoughts, and the Panthers decided not to re-sign the unrestricted free agent.

"One day it just hit me that it's time. It's time," Rucker told The Associated Press by phone. "There are about 50 different reasons why. You can think of a lot of reasons why you can keep playing, but the reasons why you should stop outweigh them."

Rucker, who played college football at Nebraska, was Carolina's second-round pick in 1999. At 6-foot-5 and 270 pounds, Rucker had the combination of size and quickness that made him one of the anchors of the Panthers' defensive line.

Rucker helped Carolina reach the Super Bowl in the 2003 season and the NFC championship game in 2005, and he ranks second in the team's 13-year history with 553 tackles and 55› sacks. He was also involved in numerous off-field charitable activities and business interests in the Charlotte area, including a day-care center he opened several years ago.

Rucker suffered the first major injury of his pro career, a torn anterior cruciate ligament in his left knee, near the end of the 2006 season. Determined not to end his career, Rucker underwent rehabilitation and was back on the field for the start of training camp seven months later.

Rucker acknowledged he was favoring his left knee early last season, but his numbers picked up once he shed a bulky brace. Rucker returned to his starting spot on the defensive line and finished with 57 tackles and three sacks.

But Rucker started wondering if he was close to retirement near the end of last season, especially after his close friend and teammate, safety Mike Minter, retired during training camp.

Rucker was in tears after what turned out to be his final home game in December, but he told reporters he would wait until a couple of months after the season to make a decision.

Rucker said in February his body felt good and he planned to play in 2008. Rucker also wanted to be in the NFL with his younger brother, Martin, a tight end from Missouri expected to be taken in this weekend's NFL draft.

But Carolina, looking to get younger on the defensive line after a next-to-last finish in the NFL with 23 sacks in 2007, did not re-sign Rucker. Second in team history with 139 games played, Rucker started to question whether he wanted to play for another team. General manager Marty Hurney sidestepped questions on Rucker during a pre-draft news conference on Monday.

The Panthers could turn to the draft to find Rucker's replacement opposite defensive end Julius Peppers.