New York Yankees closer Mariano Rivera is expected to announce his retirement on Saturday, according to sources.

The 43-year-old, who is battling an injury from a torn ACL in his right knee, will make a formal announcement at 10 a.m. from Yankees' spring training camp in Tampa, Fla., ESPN reported. He is expected to pitch against the Atlanta Braves in his first appearance this spring.

Yankees coach Joe Girardi called Rivera "the greatest closer of all time" and the player will retire as the all-time saves leader. He will enter the 2013 season with 608 saves, seven more than Trevor Hoffman's career total.

Former Yankees manager Joe Torre said Rivera had a huge impact on his baseball life.

"He basically made my career in '96 when we came up with the formula to pitch in the seventh and eighth inning,'' Torre said. "You become a much better manager when you only have to manage six [innings]. It was remarkable what we had with him and [John] Wetteland.''

Rivera took over as closer for the Yankees in 1979 and created his legacy of postseason dominance with a record of 42 playoff saves for Yankees teams that won a total of five World Series titles in his 16-year career, according to the sports report.

"It never got old for him. He may have been getting old, but the intensity, his determination, never got old," Torre told reporters in Phoenix, where he is managing the USA's World Baseball Classic team.

Rivera missed most of last season after he tore a ligament in his right knee while catching fly balls during batting practice. Part-owner and Senior Vice President of the Yankees, Hank Steinbrenner, declined to reveal what would be announced Saturday. However, he said he would like Rivera to remain involved with the team in some way even after he decides to end his playing career.

"If you hear that from me, that will be confirmed," Rivera told the New York Post after throwing a bullpen session Thursday. "It's only a rumor until I talk."

"He is the greatest closer of all time," Girardi said. "There is no question in my mind. I have had the thrill of catching him."