Nick Punto is rusty. Through the Red Sox' first 48 games, Punto made only 49 plate appearances, a fact of life given his role as a utility infielder. But when Dustin Pedroia aggravated a torn adductor muscle in his right thumb earlier this week, Punto suddenly was thrust into an everyday role at second base. And so, at 2:30 yesterday, two hours before the Red Sox took batting practice, Punto was on the field at Fenway Park, hitting breaking balls off a pitching machine and looking to finally capture the rhythm required to be more successful at the plate.