Miranda went 2-for-5 with a home run and two RBIs in the Yankees' 7-6 loss to the Red Sox at Yankee Stadium.
The 27-year-old Cuban defector has been in the Yankees' system since 2007 and had a total of 19 big-league at-bats before this season. A lefthanded-hitting first baseman, he is not going to supplant Mark Teixeira.
General manager Brian Cashman claimed during the offseason that he was willing to start the year with Miranda as his DH. But he also once said he would be comfortable with Bubba Crosby in centerfield. Then he signed Johnny Damon.
Tuesday night, Miranda singled in the Yankees' first run against Josh Beckett in the second inning for his first RBI of 2010. In the fourth, he launched his first home run of the season and second of his career, a solo shot to rightfield.
Miranda has 3 hits in 13 at-bats this season. If he gets hot, he could get the majority of the at-bats against righthanders until Johnson comes back. But Girardi still intends to rotate regulars through the DH slot.
"They all get a little excited to do it," Girardi said. "They enjoy it because they don't like to sit out a game. It's a way where they can take care of themselves a little bit better."
Said Derek Jeter: "He said, 'Excited?' I wouldn't say excited. I don't mind it. It's almost like a day off. I think that's what he uses it for. I would rather do it than have a day off."
Marcus Thames, who was expected to get at-bats in either leftfield or DH against lefthanders, is 8-for-16 (.500) as the DH. Injuries have forced the Yankees to give him more at-bats as an outfielder than they had planned.
With Johnson out, the Yankees could use Posada more at DH and put defensively superior Francisco Cervelli behind the plate. But the Yankees have rejected that notion for the time being. And the proud Posada wants no part of not catching.
"I don't know," he said when asked if it would be better if he DH'd until he was totally healthy. "If I'm able to DH, I'm able to catch. That really doesn't concern me at all. Whatever the manager wants to do."