The move didn't work out for the Yankees, as Rivera faced five batters and was charged with four runs (three earned) in Saturday's 9-7 loss to the Rays. The major point of contention was an intentional walk to pinch-hitter Evan Longoria, as B.J. Upton made New York pay with a run-scoring single.
Rivera showed some rare disagreement with the move after the game, saying that he would have preferred to pitch to Longoria, but Girardi said there was no smoothing out to be done on Sunday with regard to any potential miscommunication.
"No, because I know what he told me out there," Girardi said. "He told me that I'm the boss, and it was my decision. I don't ever expect any of my pitchers to feel they can't get somebody out, because if they feel that, we've got a bigger problem."
Girardi defended the move, saying that Upton was 1-for-7 with six strikeouts against Rivera coming into Saturday's game, compared with Longoria's 2-for-6 with a homer on May 7 and three strikeouts. But Longoria had missed two games with a left hamstring injury while Upton had 11 hits in 30 at-bats.
"I think people are probably making too much of this," Girardi said. "He's a competitor. He's Mariano Rivera. He's not going to back down from anybody. Those are the decisions that I'm paid to make."
In a sense, Rivera agreed, saying, "I want to pitch to everybody. That's why I'm not the manager."
Aside from Rivera issuing his first intentional walk since Aug. 24, 2007, there have been some points of concern with the 39-year-old closer, who is coming off arthroscopic surgery to shave an AC joint in his pitching shoulder.
The Yankees glowed when Rivera was unhittable in Spring Training, but he has been less so in the regular season. His control has been excellent, with just the one unintentional walk and 28 strikeouts in converting 12 of 13 save opportunities.
But Rivera has fared 0-2 with a 3.47 ERA while allowing 26 hits in 23 1/3 innings. Of those hits, five have been home runs, already a career high.
"It's a guy showing that he's human, to me," Girardi said. "It's part of it. It's a guy coming off surgery that's taken some time. But I still feel very good about him.
"I think because he's been so great for so long, whenever he does have a little blip in the radar screen, people say, 'Uh-oh.' That's the thing. If you're 30 and you have a blip, people don't say, 'Uh-oh.' But I think if you're older, that's always the initial reaction -- 'Is he near the end?' I don't necessarily think that."
Rivera said that he did not feel any problems with the ball coming out of his hand on Saturday. Rivera was consistently clocked between 89 and 93 mph in his outing.
"I felt good," Rivera said. "The velocity is better. It's getting better and better."
Girardi also said that he did not second-guess the decision to bring in Rivera instead of permitting starter CC Sabathia, who was at 101 pitches through eight innings, to continue. New York's lengthy two-run eighth inning played a part in that call.
"That's the life of being a manager, and that's the way the game is played," Girardi said. "I've got a great starter on the mound, and I've got a first-ballot Hall of Famer down in the bullpen. I chose to go with the guy that was fresher and didn't sit around for 25 minutes."
There was also no issue, Rivera said, with coming into a tied game instead of a save situation. As Girardi noted, if he had permitted Sabathia to continue pitching and the Yankees had lost the game, the questions would have revolved around why Girardi didn't go to Rivera.
"I don't think like that," Rivera said. "I always think that I have to give up no runs at all in that situation. If I hold it, to me, it's kind of like a save. I know the guys can score some runs."
Bryan Hoch is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.