Nelson, who the Magic signed to a three-year deal in the offseason, has a strained hamstring, groin and possibly a sore ankle.
The news comes after the Magic found out they will be without starting small forward Hedo Turkoglu, who broke a bone in his hand Friday night. Turkoglu had surgery to repair the broken bone Saturday.
Nelson missed Saturday's practice and did not participate in shootaround Sunday morning.
"I’ve just got to be smart about it," Nelson told Robbins. "I’ve been through a lot of injuries small and big. So I just have to be smart and be honest like I was today and yesterday with the training staff."
Nelson scored nine points, dished out seven assists and grabbed four rebounds 35 minutes in Orlando's 102-89 season opening victory over the Denver Nuggets Friday night.
If Nelson can't go, E'Twaun Moore and Ish Smith will likely share the point guard duties.