Penn State football fans have many questions as the Nittany Lions head into Saturday's Blue-White Game that will cap head coach Bill O'Brien's first spring practice, but one is asked more loudly than the rest.

Who's the No. 1 quarterback?

They may care that the secondary has to replace all four starters, or that there will be four new starters on the offensive line, or that there isn't much depth behind Silas Redd at running back.

Who's the No. 1 quarterback?

They may worry that the players must learn new systems on offense and defense, or that O'Brien has suggested strongly a need for the wide receivers to get open and hold on to the ball better.

Who's the No. 1 quarterback?

O'Brien inherited the top three quarterbacks - senior Matt McGloin, junior Rob Bolden, and sophomore Paul Jones - from Joe Paterno's final team. For much of the last two seasons, with Jones sitting out his first year as a redshirt and his second because of academics, Paterno didn't know, or wouldn't say, who would start from week to week.

O'Brien says he doesn't know, either, noting that none of the quarterbacks has separated himself from the others. What he won't say is how good (or bad) they have looked, but one must take into account that they are learning a new offense and going through some growing pains.

While the new coach "expects" to give each quarterback equal reps in the Blue-White Game, he's not going to guarantee it "because of how the game will be set up." So it will be interesting to see who plays first, and which of the three will get the most snaps.

The game at Beaver Stadium will be offense vs. defense with an interesting scoring system.

In addition to the usual score for a touchdown, field goal, or extra point, the offense will get two points for a play of 15 or more yards, and two points for two consecutive first downs.

The defense awards include seven points for a touchdown, six points for a turnover that doesn't lead to a touchdown, four points for a sack, two for a tackle for loss, and one for a three-and-out.

Penn State's new offense is the system O'Brien ran with the New England Patriots during his time as offensive coordinator, a high-tempo attack in which the tight end has a myriad of responsibilities in the pass game. But not much of the offense will be unveiled Saturday.

"There's 85,000 people in the stands and I'm not sure who all those 85,000 people are," O'Brien said last week, maybe exaggerating the numbers a little. "So I wouldn't expect us to show a lot. But we'll show up and we'll play hard, and I just want our guys to give a solid effort and play good football on both sides of the ball and on special teams."

Players at new positions include Curtis Drake (West Catholic) at cornerback instead of wide receiver and Bill Belton (Winslow Township) lining up at running back instead of wideout. O'Brien said both have been slowed during the spring, Drake with a shin problem and Belton with a muscle pull, but have looked good when on the field.

With all the talk about quarterbacks and the offense, the defense has been overlooked. But the Nittany Lions' front seven should be strong, with defensive end Pete Massaro (Marple Newtown) back from a torn ACL and a returning group of linebackers that will be better when Michael Mauti, who suffered a torn ACL last season, returns in August for preseason.

But much of the attention Saturday will go to the guys wearing the red (do not hit) jerseys - McGloin, Bolden, and Jones.

"They work really hard," O'Brien said. "They're all smart guys. It's been fun to be around them. But they have to just continue to try to be consistent and make good decisions and throw the ball accurately. And that's probably the guy that we would go with" as the starter.

"There's not a clear separation there," he added, "but there will be. Eventually, there will be."

Contact Joe Juliano at 215-854-4494 or jjuliano@phillynews.com or follow him on Twitter @joejulesinq.