The New York Times reported that Rivera had a MRI performed and could need minor arthroscopic surgery, although the newspaper said the procedure would be minor and would not be expected to affect Rivera next spring. Girardi used Rivera four times in five games before the Yankees were eliminated from postseason contention this week.
"It hasn't been a concern," Girardi said. "He would be here. If we were still playing for something, Mo would be here and he would have been available. Would I have pitched him [Wednesday] after throwing four out of five games? Probably not. Would I have pitched him [Thursday]? Probably, yes."
Girardi said that it was possible that Cashman had been able to review medical information on Rivera that was not available in Toronto. He has been sensitive of criticism regarding how he has handled player injuries with the media in his first season with the Yankees.
His tone grew sharp and Girardi slammed his fist when repeatedly questioned.
"I am not hiding anything from you," Girardi said. "I'm going by what the player told me. That's all I can do. I don't care if you believe me. I'm telling you what the player told me. That is it. If you don't like it, there's not a whole lot I can do. I'm the manager, I have to answer the questions. I'm answering the questions with the knowledge I have."
Girardi said that Rivera told him on Tuesday that his whole body felt "cranky," but that in and of itself was not an issue as he completes a season that saw him fare 6-5 with a team-leading 1.43 ERA, converting 38 of his 39 save opportunities and pitching in 63 games overall.
"I don't have concern," Girardi said. "Mo's shoulder or body has been cranky before. We had to shut him down earlier this year with back spasms in the back of his shoulder. He had some minor discomfort. To me, I'm not concerned."
Rivera is expected to rejoin the Yankees on Friday at Fenway Park, as the club opens its final three-game series of the season against the Red Sox.
Yankees reliever Jose Veras, a friend of Rivera's, said that he did not believe Rivera's situation was major.
"I think it is not a big deal," Veras said. "He just felt a little sore and went to check to make sure that everything is normal. I don't think it's a big deal. I think it's going to be OK.
"He can pitch, but he doesn't want to keep pitching like that, you know what I mean?" Veras continued. "He made sure that he went to check. Hopefully he'll be OK and I think he's coming [Friday]."
Girardi said he assumes Rivera is available to pitch this weekend. He especially would like to have Rivera on board for Sunday's finale, as Mike Mussina makes an attempt to secure his 20th victory.
"Believe me, if I was concerned that I was going to hurt this guy ever, I would never pitch him," Girardi said.