"They're not where they need to be," Fulmer said. "We actually moved Chase Nelson in there yesterday (Monday) to create some more competition, give us another guy to compete."
Mapu is a warrior but lacks the conditioning following his two-year hiatus to play more than 20 to 30 snaps per game. In terms of his stamina, Fulmer said, "J.T. is not quite where he needs to be."
Bolden was a heralded prospect as a high school senior, then spent a year at prep school. He has tremendous potential but has not shown the down-after-down production Fulmer demands. The same holds true for Williams.
"It's a maturity process,"Fulmer said. "We can sit here and let them wait to be juniors before they get to play ... or we can turn the screws and get them to respond. Then we can have a couple of really good years BEFORE they're juniors."
Fulmer said Bolden made "a couple of real fine plays in the Cal game, which was good to see," but added that both Bolden and Williams tend to play "like a rollercoaster," up one minute and down the next.
"I'm not saying they aren't trying," the coach added. "They're just not consistently practicing at a level that will get you in the ball game."
Although he lacks heft and experience, Nelson shows signs that he might be able to contribute at defensive tackle pretty soon.
"Chase has some natural quickness," Fulmer said. "He comes from an outstanding program. He's a little undersized but he's aggressive. I want somebody in there who's going to mix it up."