ALAMEDA, Calif. (AP) - Oakland Raiders quarterback Bruce Gradkowski sat out practice Wednesday with an injured right shoulder that could sideline him for this week's game against the San Francisco 49ers.
With Gradkowski nursing the injury, Jason Campbell is approaching this week as if he will start. Campbell came in late in the first quarter last week after Gradkowski was knocked out with a hard hit by San Diego's Shaun Phillips and led the Raiders to a 35-27 win.
Gradkowski had an MRI on Monday and the Raiders (2-3) hope to have a better idea about his status against the 49ers (0-5) on Thursday.
"We have a pretty good idea," coach Tom Cable said. "Obviously he didn't practice today and I think he's pretty sore so we'll see what kind of progress we make in the next 24 hours."
Gradkowski's injury could give Campbell a second shot at being the starting quarterback for the Raiders. He got benched just six quarters into his career with the team, but did not mope about his misfortune, choosing to do a "self-evaluation" about his own shortcomings.
"Coaches made a decision and as a player the only thing you can do is just go out there and keep competing, not get down on yourself and think you're not worthy of being a starter or being a great player," Campbell said. "It's just a decision that was made. You do everything you can to support your teammates and you keep fighting forward, and when the time comes again, just make the most of it."
Campbell did that, completing 13 of 18 passes for 159 yards and one touchdown in his first career relief appearance. He led the Raiders on touchdown drives of 97 and 73 yards in the second half, helping Oakland snap a 13-game losing streak against San Diego.
Both of Oakland's wins this season have come from backup quarterbacks, with Gradkowski rallying the team to a win over St. Louis after replacing Campbell in the home opener. That prompted Cable to harken back four decades to when George Blanda frequently relieved starter Daryle Lamonica late in games and led the Raiders to victory.
"It's great because we have two guys who are proven starters, two guys who will go in there and get the job done," running back Rock Cartwright said. "If one guys goes down, the other guy has to step in and make plays."
While the Raiders run essentially the same offense with both quarterbacks, the results are different. Gradkowski does a better job extending plays with his feet and getting the ball downfield to the receivers.
Campbell is more apt to check down to safer options, with 53 of his 70 passes going 10 yards or less downfield, according to STATS LLC. He is just 5-for-17 for 140 yards and an interception on passes longer than 10 yards.
Gradkowski has more than twice as many attempts down the field, with 16 completions for 294 yards and two touchdowns on his 38 attempts of at least 10 yards.
"You can't get discouraged if the ball is not getting to the outside a lot because there will come a time when it will get on the outside," Campbell said. "You can't really get caught into who's catching it and who's not catching it."
The Raiders acquired Campbell in a draft-day trade with Washington and anointed him the starter before the beginning of training camp. The first signs of trouble came when Campbell was knocked out of the exhibition game against the 49ers with a stinger and a sore wrist after a hard hit from Travis LaBoy.
Gradkowski came in and threw two touchdown passes, once again delighting the fans he won over the previous year with his performance in place of JaMarcus Russell. Campbell then struggled at the start of the regular season, leading the Raiders to just 16 points before being benched at halftime of the second game of the season.
Campbell admitted that he wasn't completely healed when he came back and that could have been a factor in his early season play.
"It's always in the back of your mind," he said. "Just because it was still there. It wasn't 100 percent yet. Right now, I feel 100 percent. Injuries always play a part in the back of someone's mind. But it's over now."
Notes: RB Darren McFadden was back at practice in a limited fashion after missing last week's game with a hamstring injury but would likely back up Michael Bush this week if he's good enough to go. ... Cable is optimistic OL Robert Gallery can return for the first time since injuring his hamstring in the season opener.