PROVO — For the third straight week, junior Riley Nelson will start at quarterback for BYU.

Coach Bronco Mendenhall said Tuesday that Nelson will be the starter, but that freshman Jake Heaps will also play when the Cougars visit Florida State on Saturday.

"Riley will still get the first snap. From there, we've never guaranteed that whoever gets the first snap will end up playing the most," Mendenhall said. "It's worked out that way the past couple of weeks. But that doesn't mean that will be the way it will always be."

The coaching staff has been devising a plan to use both Nelson and Heaps — but instead of alternating series, the rotation between the two QBs will be determined by the situation.

Exactly how both quarterbacks will be used against Florida State is "still a work in progress," Mendenhall said. "It will most likely take on a little bit more situational emphasis rather than the every other series approach that we were starting with."

While Nelson has started both games this year, Heaps alternated series with Nelson against Washington and in the first half at Air Force. Nelson played the entire second half in the Cougars' 35-14 loss to the Falcons while Heaps watched from the sidelines. BYU passed for just 88 yards in that game.

"I think the coaches are doing the best that they can and what's best for both me and Riley," Heaps said. "You trust in your coaches. You just follow your head guy. You're going into battle with them. Whatever he says, you're going to go do. That's all I'm worried about right now."

INJURY UPDATE: Going into the FSU game, linebacker Brandon Ogletree is questionable after sustaining an MCL sprain in his knee against Air Force.

Head trainer Kevin Morris said offensive tackle Matt Reynolds was severely ill in the days leading up to the game against the Falcons.

"He was really sick Thursday and Friday. Friday night, we ended up putting four bags of IV fluid in him just to try to get him to go Saturday," Morris said. "He did really well except for the one time he cramped up on the field. I give him a lot of props for playing."

EXTRA POINTS: The Cougars haven't beaten an Atlantic Coast Conference opponent since defeating Georgia Tech in Provo in August, 2003. ... The last time BYU downed an ACC foe on the road was in September 2000, with a 38-35 overtime victory at Virginia. ... Linebacker Shane Hunter's third-quarter interception of Air Force quarterback Tim Jefferson was Hunter's first career pick. It was also the first turnover BYU forced in 2010.