The injury occurred after Nova tried to field a comebacker -- though it's unclear whether he hurt the ankle while planting himself to field the ball, as a lingering effect to being hit by a grounder there on July 7 or both.
But the fact the 24-year-old pulled up lame, then was immediately taken out after giving up a run in 1 1/3 innings, was a clear indication to Girardi that Nova will at least miss one start.
Girardi just isn't sure if Nova will be out even longer than that.
As a budding prospect who had success as a starter in the Majors this season, Nova wasn't just a fallback option in case one of the Yankees' current starters struggled. He was a prime candidate to pitch in a split doubleheader on July 30 against the Orioles.
That could still happen, since Girardi doesn't necessarily feel Nova would have to pitch another game in the Minors before being called up for an emergency start. But it'll all depend on how Nova feels moving forward.
Nova was 8-4 with a 4.12 ERA in 17 games (16 starts) for the Yankees, then went 1-2 with a 3.38 in his first three Minor League starts.
Eric Chavez, recovering from a bone bruise in his foot, had an impressive second rehab game on Wednesday, notching four singles in five at-bats while serving as the designated hitter for the Class A Tampa Yankees.
Girardi, who doesn't expect to have Chavez or Rafael Soriano back for the weekend home series against the Athletics, isn't sure when Chavez will play the field, but was encouraged by his latest line.
"The positive thing for me there is that he was able to give you five at-bats, where the foot didn't get sore," Girardi said. "That's the positive thing for me. Obviously the hits are a positive as well, and he's getting his timing back. But that he can continue to run the bases and not get sore, that's important to me."