Confronted with both a logjam on the 40-man roster and a bevy of useful candidates, the Yankees must make “some tough decisions” as they fill out their Opening Day bullpen later this week, manager Joe Girardi said. In that vein, Girardi offered a tepid endorsement of reliever David Aardsma, long considered by outsiders likely to make the club. Girardi is often effusive when praising his players. He opted for a more measured tone with Aardsma, who saved 69 games for Seattle from 2009 to 2010, but missed most of the last two seasons due to injuries. He dealt with a groin injury earlier this month. “He’s been okay,” Girardi said. “I know he had that little setback, where he had to miss about a week with [an issue] with his groin, but he’s been okay.” As of now, the team has four locks for the bullpen: Mariano Rivera, David Robertson, Joba Chamberlain and Boone Logan. Despite a rough spring, Cody Eppley is another strong possibility. Adam Warren has a chance, as the team could use a long reliever with David Phelps moving to the starting rotation at the outset.