From NFL.COM
"Under doctor orders, he won't participate in Saturday drills but is hopeful to do so on Sunday, a source informed of his situation told NFL Network Insider Ian Rapoport. The good news for Barnett is that defensive linemen are scheduled for the bench press only on Saturday in terms of physical testing, with the majority of drills at that position set for Sunday. Other appointments on the Saturday itinerary for defensive linemen include psychological testing, a meeting with the NFLPA, and media interviews.
A weakened Barnett was up at 5 a.m. Saturday and trying to hold fluids down, per Rapoport.
ESPN first reported news."