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Kristin Murphy, Deseret News
BYU football practice at BYU in Provo on Saturday, Aug. 4, 2012.

PROVO — BYU senior quarterback Riley Nelson didn't seem like a happy fall-camper Saturday.

While he said he likes the way the offense is progressing overall, Nelson definitely has concerns about the offensive line.

That's because several O-linemen have not been participating fully due to injuries or other reasons, causing the coaching staff to play a variety of personnel groups, and creating a lack of continuity.

Nelson expressed some frustration about that after Saturday's practice.

"It all starts up front. I haven't had the same five guys in front of me from one day to the next," Nelson said. "That's frustrating. But at the same time, there's nothing I can do to control that, so I can't worry about that. Neither can the coaches or the other players. It's up to each one of those guys to do what they've got to do to get back on the field. In some cases, that's rest and letting an injury heal. In other cases, there are things they can do that they can control and they need to do that. The sooner the better, as far as the offensive line is concerned."

A number of projected starters have been slowed by injuries, including right tackle Braden Brown (ankle sprain), left tackle Ryker Mathews (sore neck), center Houston Reynolds (shin soreness), right guard Brock Stringham (ankle sprain) and backup tackle Walter Kahaiali'i (knee soreness).

Coach Bronco Mendenhall said none of those injuries are severe enough to prevent them from playing in the season-opener against Washington State on Aug. 30.

During spring ball, BYU's offensive line was decimated by injuries and offseason surgeries. There were so few O-linemen available that it limited what the offense was able to do.

During the offseason, the coaching staff had the linemen slim down so they could be more mobile.

"They are trimmer and they're more fit and there's more of them," Mendenhall said Saturday. "Not only more players, but more depth. So it's good."

But because they've had so little time together as a group, cohesion is a question mark.

"Of course it's a worry, but there's nothing we can do about it," Nelson said. "We'll just keep getting work with the guys that we have. In the meantime, hopefully those guys are doing everything they can to get on the field. We need them, that's for sure."

Since Thursday's scrimmage, the coaching staff has been in the process of solidifying the depth chart. But the absence of key offensive linemen is making it tough, according to Nelson.

"It's been a focus up to this point, we just can't seem to do it," Nelson said of the depth. "We've got to get over the hump. I don't know, though. That's why they pay the coaches the big bucks, is to make those decisions, to decide when a guy needs a rest, when a guy needs to come out, what requirements to set for those guys and what requirements they have to meet to play on the field."

During Saturday's 11-on-11 session, Nelson completed 6-of-7 passes for 70 yards and three touchdowns, to Cody Hoffman, Mitch Mathews and Kurt Henderson, respectively. Running back Michael Alisa had a 12-yard TD run.

A poor handoff exchange with Alisa caused a fumble that was recovered by cornerback Preston Hadley.

Besides the concerns with the O-line, Nelson is optimistic.

"I'm happy with the progression of the offense," Nelson said. "I think (offensive coordinator Brandon) Doman is, too. Just keep getting better. Onward and upward every day."

BYU camp report

Day 9: The Cougars practiced Saturday morning in a session that included a lot of red zone work.

Standouts: Quarterback Riley Nelson completed 6-of-7 passes for 70 yards and three touchdowns — to Cody Hoffman, Mitch Mathews and Kurt Henderson. Running back Michael Alisa had a 12-yard TD run. Defensive back Preston Hadley recovered a fumble by Alisa on a poor handoff exchange.

Injuries: Tight end Marcus Mathews remained sidelined while dealing with an illness.

Overheard: "You have to conserve your energy where you can conserve it. Forgive me for not having as many quips as normal. Let's just say I'm grateful for the Sabbath." — Quarterback Riley Nelson, when asked why he seemed "a little despondent" during his conversations with the media on Saturday.

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