The vice-captain was forced off early in Saturday's 4-0 win over Nurnberg, but has made a quick recovery and looks set to feature in the showdown with the Italians
The Germany international picked up a calf injury in Saturday's 4-0 win over Nurnberg, and was forced to be substituted after 71 minutes.
Coach Jupp Heynckes initially feared the worst, but later told the club's website that "it is already much better".
Schweinsteiger missed training on Sunday, as did centre-back Daniel Van Buyten, who was suffering from a bruised foot. The pair are expected to return to full training by Tuesday, and then to feature against Napoli the following day.
Additionally, defender Breno trained with a ball on Sunday for the first time since he was arrested for suspicion of arson. The 22-year-old has undergone psychotherapy and is nearing a return, but he will not make the bench for the Napoli match.
Kick-off at Munich's Allianz Arena is scheduled for 19:45 GMT on Wednesday.