But on Thursday afternoon, Rivera did something different when asked about the injury: He smiled.
"I feel good (Thursday), I feel good," said Rivera, who will be available to pitch against the Tampa Bay Rays on Thursday night after missing the past three games due to his sore right triceps, which began acting up on Monday. "(I'm) not 100 percent, but I feel good. I'd say I feel like 90 percent or 95 percent. I think that's good enough."
Rivera hasn't pitched since last Sunday afternoon, when he blew a save against the New York Mets. He had hoped the soreness wasn't anything significant, but it proved to be too much to bear, causing Rivera to miss the Yankees' entire three-game series with the Cleveland Indians.
"I thought it was only a little thing, for sure," said Rivera, who is 1-1 with a 1.91 ERA and has converted 21 of 25 save opportunities this season. "I was a little disappointed when I knew it wasn't one day."
Rivera was seen wearing a massive heat wrap on his right arm before he threw on Thursday afternoon, and said he's been receiving daily treatment.
"You guys don't want to know how much (treatment)," Rivera joked. "A lot. I just need to stay on top of it and do my treatment."
Rivera said the injury may be one he has to deal with all season, which is why he's decided to skip the 2011 All-Star Game in Phoenix. Rivera was chosen by the American League's manager, Texas Rangers skipper Ron Washington, as his closer.
"I'm not gonna go because I wanna make sure I'm 100 percent, and the three days will be good to rest," Rivera said. "I'm [telling] you guys first (before I inform the league), but I'm gonna talk to Ron Washington and tell him 'Thank you for choosing me.' ... It's never an easy decision, but at the same time, you wanna make sure you're 100 percent. You don't want to go there and be 95 percent."
Rivera called Thursday afternoon "the first day that I feel the best," and said he's not thinking about the injury at this point, "just pitching."
But Rivera said he doesn't know exactly how he'll respond physically until he gets out there and "tests it out" on the mound in an official game setting.
Rivera said he's not going to get any further tests on his sore right biceps.
"I don't think it's gonna be necessary because it's progressing," Rivera said.
Mike Mazzeo is a regular contributor to ESPNNewYork.com.