Ahmad Brooks, who had two sacks, seven tackles (three for loss), a pass defensed and two quarterback hits in the 49ers' 27-6 victory, said he doesn't believe Griffin has fully recovered from his knee injury suffered last season and shouldn't be on the field as a result.
"He's obviously a man and he makes his own decisions, but I personally don't feel he should be playing right now," Brooks told CSN Washington.
Griffin threw for just 127 yards on 17-of-27 passing with one interception and was sacked four times in the loss. Aldon Smith had the other two sacks for the 49ers.
"He's a man, he has the heart of a warrior and is going to go out there and play regardless of the circumstance," Brooks told CSN Washington. "Everybody can see it. Everybody can see it. He shouldn't be playing."
Griffin's struggles have been a popular topic around the league. Baltimore Ravens defensive lineman Chris Canty told NFL Network on Tuesday that the Redskins should sit Griffin in favor of Kirk Cousins.
"It's clear that RGIII does not have the explosion that he had during his rookie campaign," Canty said. "It's clear that he's not able to run the offense at the high level that he did during his rookie year. I think Kirk Cousins gives them the best opportunity to win football games right now."
Griffin started Monday's game with four incompletions. When he finally completed his fifth pass, the play lost a yard. His sixth attempt was intercepted.
"We've got to conquer some of the demons that we have going on as an offense," Griffin said, "and just as a team in general."
The interception was Griffin's 11th pick this season, more than double his total of five for all of 2012. He still is without a rushing touchdown this season. He had seven last season. On Monday, Griffin ran six times for 22 yards.
"What am I supposed to do, come up here and talk about how bad we are? That's not my job," Griffin said at his news conference, his gold jersey pants covered with splotches of grass stains thanks to the four sacks and more than a half-dozen other hits.
The performance followed a week chock-full of even-greater-than-usual scrutiny for the reigning NFL Offensive Rookie of the Year. His use of pronouns was parsed (as in, how often he says "I" or "me" as opposed to "we").
On Monday he said, "Right now, we're shooting ourselves in the foot way too often. It's a team game, and we have to play better team football."
His relationship with coach Mike Shanahan was interpreted plenty, too.
"People are trying to character assassinate me," the man known as RG III said, "and it's unfortunate."
Information from The Associated Press was used in this report.