The five-time Pro Bowl quarterback likely will miss the rest of the week's organized team activities.
Kevin Kolb, a second-round pick last season, worked with the first-team offense in McNabb's absence.
McNabb hasn't played an injury-free season since leading the Eagles to the Super Bowl in 2004.
He missed the final seven games in 2005 with a sports hernia; sat out the last eight games, including the playoffs, in 2006 with a torn knee ligament; and missed two games last season with a sprained ankle and injured thumb.
Eagles sue T.O. to recoup 2004-05 bonus money
Brewers shut down Gagne with shoulder tendinitis
