CSNPhilly.com, which first reported the injury, said there's a possibility Babin will miss the entire preseason.
The Eagles announced on Monday that an MRI confirmed that Babin, who was injured in drills Saturday, had a calf strain. According to the reports, Babin specifically has a Grade 2 strain, which by definition is a partial tear of the fibers in the calf muscle.
Babin had a career-best 18 sacks last season after rejoining the Eagles as a free agent. He was selected for his second straight Pro Bowl.