Joe Semanoff is also sitting out spring camp to heal an injured shoulder. Harvey Unga is participating, but only in non-contact drills as he continues to nurse a hip bone that was broken at the tip in last year's game against Boston College.
But the fact that three key running backs are mostly out might turn out to be a positive thing, said running backs coach Lance Reynolds.
At the very least, it will give coaches more time to evaluate the other candidates to replace all-time school rushing leader Curtis Brown as BYU's go-to back.
"It is open right now, partially because I don't know who is going to be healthy," Reynolds said. "When we do have everybody back, we will have five to six good backs."
Junior Manase Tonga has gotten the most work with the first unit, and said he is ready to play fullback, tailback or a mixture of both should Vakapuna continue to be slowed by the injury that plagued him much of last year.
"If anything, my role will be like you saw a glimpse of at the end of last year, where I got a certain amount of carries and did a bit of everything," Tonga said. "With Fui out of spring camp, I am probably the main guy, which is OK with me. I am comfortable with that. I know I can be the go-to guy. I don't know if that means I will be filling Curtis' shoes or not. My main focus is to be consistent and help make the others around me play better."
Fellow junior Ray Hudson, more of a true tailback, could also be a factor. Hudson said he has spent the offseason working on his strength and speed.
"Some people say that because I am a speedy type back, I might replace Curtis," he said. "I got quicker and more explosive in the offseason. I have been squatting [weights] a lot. I will be more explosive than ever. I see this as a huge opportunity to help the team."
Said coach Bronco Mendenhall: "I don't see us as rebuilding at that position. I see it as reloading."
Reynolds said another player who is not participating this spring could also have a big impact: incoming freshman J.J. DiLuigi, although the much-decorated California running back might also be used at slotback in BYU's offense.
"We are seeing on film, when you watch him, that he could do either," Reynolds said of the prized recruit. "He's got great feet, great change of direction, great make-guys-miss ability. He could play the slot or running back or both. He's not a little guy. He's a stout dude."
The coach said Vakapuna should be ready to go in May or June, while Unga "looks and appears as though he will be at full strength in a month or two."
Mendenhall reiterated Tuesday that just because Max Hall worked with the first unit Monday and Cade Cooper took his turn Tuesday, a favorite has not emerged in the race to be BYU's starting quarterback.
"Our plan is to go every other day with Cade and Max as the [No. 1] quarterback," he said. "After two days, am I ready to say who is ahead and who is behind? No. I think it is dead even at this point."
Mendenhall acknowledged the position is the most visible on the team and receives the most exposure, but said it will be handled the same as competition for any other starting spot.
"When a player emerges that clearly becomes the starter, then we will move forward," he said.
Cooper, the transfer from Snow College, looked sharp in 11-on-11 scrimmages Tuesday with the first team, despite some pretty healthy wind gusts.
"Confidence is growing as Cade gets more reps," Mendenhall said.
BYU released its 2007 schedule along with all the other teams in the Mountain West Conference on Tuesday, but Mendenhall was not willing to acknowledge any peculiarities, advantages or disadvantages.
"We will play who we are supposed to play, whenever we are scheduled, whether it is at night or on TV or on the road or at home. We look to defend our championship," Mendenhall said.
The team opens with two Pac-10 opponents, Arizona and UCLA, and has a bye after its fifth game. It doesn't start MWC play until Sept. 22, against Air Force, and goes about a month, from then until Oct. 20 without a home game.
No team has a bye before it faces the Cougars this year, unlike in past years, but Mendenhall said that perceived advantage makes no difference to him.