Jackson last year became the first player in NFL history to make the Pro Bowl at two positions -- receiver and punt returner. Jackson also missed both sessions Sunday.
Two others starters, middle linebacker Stewart Bradley and cornerback Asante Samuel, also were held out of practice Monday morning because of hamstring spasms. Bradley hadn't practiced Sunday, either, and Samuel also left practice Sunday with his injury.
Reserve running back Mike Bell strained a hamstring Sunday and didn't practice Monday morning.
Defensive tackle Antonio Dixon suffered a head injury, and defensive back Macho Harris injured a hamstring during the afternoon session.
Guard Max Jean-Gilles returned after leaving Sunday's practice early because of dehydration. Tight end Brent Celek departed Monday morning's practice early, also because of dehydration, but was available in the afternoon.
Copyright 2010 by The Associated Press