Cashman went on SiriusXM's MLB Network Radio with hosts Jim Duquette and Mike Ferrin, and said Rivera is "not coming back this year," contradicting reports from Rivera's rehab doctor. Earlier this month, Dr. Keith Pyne told Joel Sherman of the New York Post that Rivera was ahead of schedule in his recovery from a torn ACL in his right knee, and could make it back in 2012.
In response to a question from Duquette about that report, Cashman called Pyne's comments "unprofessional."
"I mean, medical personnel should be quiet," Cashman said. "And it's not our physical therapist, it's someone he's got that we've signed off on. But those guys should not be doing interviews, and he provided an interview that was ... not a fair reflection of where this player's at. His over-enthusiasm, I thought, provided improper information.
"He's not coming back this year and I wish he was, I wish he was, but unfortunately people get excited. They want to get their name out there for whatever reason, and so he got a day in the sun, but he'll be proven wrong in the end unfortunately."
Rivera already addressed Pyne's comments by saying his goal was to return this season and that he would be "disappointed" if he could not.
"I'm working. I'm feeling good," Rivera told ESPN Radio's Michael Kay. "That's all I can tell you. I feel good and the therapy is great. Everything is good. You have to continue working hard and wait to get on the field."
Andrew Simon is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.