It appears that one of the great careers in baseball history will be ending this year. Mariano Rivera is expected to announce on Saturday that he intends to retire following the 2013 season.

The Yankees have scheduled a news conference to be held at 10 a.m. ET on Saturday at George M. Steinbrenner Field in Tampa. The club has not commented on reports of Rivera's plans or the subject of the news conference.

Manager Joe Girardi acknowledged the news conference but declined to divulge the topic, saying that the person holding it should be the one to divulge the topic. Nonetheless, he certainly didn't deny the reports that it would center on Rivera.

"Greatest closer of all time," Girardi said when asked his thoughts on Rivera. "No question in my mind. I've had the thrill of catching him, and I was there when he really burst onto the scene and was a dominant setup man. To see what he's done as a closer has been a thrill for me. I know there's a press conference on Saturday and we'll go from there."

ESPN.com and the New York Post are among the outlets reporting that Rivera will announce the end of a career that has spanned 18 seasons, all of them with New York.