Scott Audette/Reuters Mariano Rivera during a workout in February in Tampa.

JUPITER, Fla. — The Yankees have scheduled a news conference for Saturday morning in Tampa where Mariano Rivera is expected to make it official that he is retiring after this season.

With a major league record 608 saves, Rivera has carved out what may have been the greatest career ever by a closer. His entire professional career was spent with the Yankees, and he was an integral part of five championships.

"He's the greatest closer of all time, no question in my mind," said Joe Girardi, his manager and former catcher. "He's one of the best pitchers of all time, not just closers, and one of the best teammates, and a lot of fun to catch."

Rivera, 43, was hinting last spring that 2012 would be his last year, but after a season-ending knee injury on May 3, he declared he would come back in 2013.

When he arrived at spring training this year, he again said he would reveal his plans for the future.

The Yankees are prepared for a big send-off, but knowing Rivera they have left open the possibility that he could change his mind at the last minute. Still, every expectation is that he will announce this will be his final season.

What made Rivera even more special was the fact that he primarily used one pitch, the cut fastball, to achieve his unprecedented success, which includes 42 postseason saves and an uncanny 0.70 earned run average in 96 appearances.

Ichiro Suzuki played against Rivera for virtually all of his 11-year career when he was with the Seattle Mariners and said that when people in Japan asked who was the toughest pitcher he faced in the majors, he would say Rivera.

"Everybody knows that he used one pitch and one pitch alone," Suzuki said through his interpreter. "Nobody has ever had this much success with one pitch in the past, and no one will ever have this much success with one pitch in the future."