One day after Rodriguez tied former teammate Ken Griffey Jr. for fifth place on the all-time list with his 630th career home run, Girardi slotted the 36-year-old slugger in as the designated hitter for Saturday's matinee against the Angels.
"You just kind of try to watch how he's moving in his at-bats," Girardi said, "[and] if you feel like there's that explosiveness in everything that he's doing -- it's really watching really closely, how your perception of how a guy feels and then talking to him and making that decision with their input."
Rodriguez has been using what he calls a "less is more" approach with his workouts, hoping to avoid a repeat of a frustrating 2011 season in which he missed 38 team games after undergoing right knee surgery on a torn meniscus in July.
"I take it one day at a time," Rodriguez said. "For me, it's all about health and feeling good. There's no question in my mind that if I'm healthy and have my legs under me that I can play at a high level and help the team win."