Mariano Rivera is another step closer to what he has said will be a comeback from a torn ACL.

The Yankees closer said Tuesday that he had successful surgery on his right knee, almost six weeks after he hurt it shagging fly balls in Kansas City.

"My surgery was a success, it went perfectly," Rivera wrote on Twitter. "I am looking forward to beginning my rehab soon. Thanks as always for your prayers."

Things looked bleak for Rivera, who was carted off the field after going down during batting practice May 3, until he ended speculation he would retire by saying a day later: "I'm coming back. Write it down in big letters. I'm not going out like this."

The 42-year-old is Major League Baseball's all-time saves leader with 608 and has a record of 76-58 with a 2.21 earned run average and 1,119 strikeouts in 18 seasons, all with the Yankees.