Do Bucs have a No. 3 pass-catcher?

Rookie Mike Glennon was supposed to be buoyed as the starting quarterback for the Tampa Bay Buccaneers by receivers Vincent Jackson and Mike Williams. However, after being limited this week by a hamstring injury, Williams was completely held out of Friday's practice. Assuming his absence was due to his hammy, it's fair to wonder whether he will be available Sunday, when the Bucs face the Philadelphia Eagles. Who would step up in his absence?