Victorino returned Tuesday to Philadelphia, where the injury was diagnosed by a hand specialist. A grade-one sprain is the least severe.
"He's feeling better," Proefrock said. "We will make a decision on what our course of action will be with him in the next 48 hours."
Victorino was hurt Sunday when he stumbled and fell making a throw in Toronto.
"He can't grip the ball, and it's hard to grip the bat," manager Charlie Manuel said.
Victorino was replaced in the starting lineup by Michael Martinez, who has four RBIs in the past two games.