NAPA — Second-round pick Menelik Watson's first practice of training camp lasted less than 30 minutes Wednesday before the Raiders' offensive lineman left the field after re-injuring a calf muscle in his left leg.
Watson, the 42nd overall pick and projected backup to right tackle Khalif Barnes, had been on the non-football injury list since the beginning of camp after injuring his calf in mid-July.
The 6-foot-5, 315-pound tackle jogged out to practice and took part in two offensive linemen drills before aggravating his injury. Watson angrily walked off the field with head trainer H. Rod Martin, punched a wooden bench near the team's weight room and let out a scream before going into the locker room.
A few minutes later Watson sat on the ground in the shade just outside a door of the locker room, his head down in obvious disappointment.
"This is not the way I planned on my first training camp, I've not even took a snap yet," Watson said. "It's very frustrating, especially after the spring, making good strides in the spring. I wanted to get out there and get on the field."
Watson insisted he had not hurried back after missing the first 10 practices.
"I was aware of the situation and that I had to be careful," Watson said. "I talked about it with the training staff, that we were going to take it slow. You get out there and you get your juices flowing and you're trying to push it ... and it happened."
Defensive tackle Pat Sims, also making his first appearance of camp after being taken off the physically unable to perform list, didn't last much longer. He sustained an apparent hamstring injury during blocking drills and missed the rest of practice.
Raiders coach Dennis Allen hasn't ruled either player out for the preseason opener Friday night against Dallas.