Quarterback Jason Campbell is expected to be back at practice on Monday, two days after leaving the preseason game with a possible concussion.
Campbell took a knee to the head on a scramble play late in the second quarter and did not return to the game. He took concussion tests after the 17-3 loss Saturday night and Jackson said he thought his quarterback would return to practice on Monday.
"It's a huge relief," Jackson said. "Anytime a guy goes out and needs to be checked, you want to make sure the next day that everything is going to be OK. He's going to be well."
The news was not as good for tight end Kevin Boss, who has a sprained left knee after being hit by a helmet and will be evaluated on a week-to-week basis.
There weren't a lot of positives to take from the second preseason game for the Raiders. The offense failed to score a touchdown and the defense got run over all night and couldn't get off the field.
The Raiders were outgained 402-214 in the game and allowed 239 yards rushing. While much of the damage came against reserves, the first-team defense also struggled to stop the Niners as Oakland is having trouble building the bully that Jackson has talked about ever since getting the head coaching job seven months ago.
"You don't build a bully overnight," he said. "You don't build a bully in two days or two preseason games. Don't get me wrong, these preseason games are very important and they all matter. But I know come September 12, they truly matter and I think our team understands that we need to make some strides and we need to get better and we need to keep working. We're a work in progress."
While the offense has struggled at times this preseason with just one touchdown in two games, part of that can be attributed to a series of injuries to key players.
Campbell played two-plus series against the Niners, going 5 for 7 for 74 yards with two sacks. He went three-and-out on his first possession, couldn't score after getting first-and-goal from the 2 on the second drive and then got hurt with the Raiders moving on the third possession.
"There's a lot of stuff that we're not even doing right now," Campbell said after the game. "You got to understand that we have a lot of key guys out right now -- Darren and three of our top receivers. It's not the same guys that are all going to be out there in one unit so there's a lot of things that we do that we're not doing right now in the game."
The defense has been healthier, with 10 of the 11 starters from Saturday night expected to start when the regular season opens Sept. 12 in Denver.
That's what made the porous run defense so glaring. Jackson said he might stage a few live tackling sessions in practice this week to help shore up that unit.
"When the players see the tape they'll understand exactly what it is that we need to do," he said. "I know it sounds like a broken record but trust me we're going to get this fixed."
The biggest plus once again came from rookie receiver Denarius Moore, who had two catches for 28 yards and returned a kickoff 48 yards. The fifth-round pick from Tennessee has been a star in training camp and that has carried over so far in two preseason games.
"He's a bright spot," Jackson said. "He's done some really good things. The guy, when we throw it to him, he catches it. When he returns it, he's a threat. I think he's a very solid and good football player. Again, he's got to be consistent and keep doing it week in and week out. So far, so good."
Copyright 2011 by The Associated Press