"I have no idea how long it's going to take. I don't know," Jackson told reporters. "We know he won't be here next week."
Campbell left the game during the second quarter when he landed hard on his right shoulder at the end of a 7-yard run. Campbell was in obvious pain as he walked gingerly off the field with trainers, holding his right arm close to his body. He immediately headed up the stadium tunnel into the locker room.
Campbell started the game 6-of-9 passing for 52 yards. He was replaced by Kyle Boller, who went 8 of 14 passing for 100 yards.
"It's unfortunate Jason got hurt. I feel for him, I really do," Boller said. "It's unfortunate it happened. But now it's my job to lead this offense."
Jackson wouldn't necessarily commit to Boller when asked about the quarterback position going forward, saying he would do whatever gives the team the best chance to win. According to La Canfora, the Raiders might pursue a veteran ahead of Tuesday's trade deadline.
The only other quarterback on Oakland's roster is rookie Terrelle Pryor, who will be activated Monday. Pryor got a one-week roster exemption after serving a five-game suspension to start his career.
The Associated Press contributed to this report.