It was Clark himself. The Nittany Lions' 2009 All-Big Ten quarterback is living in town while waiting for the NFL Draft later this month.
And his very appearance Saturday only served to accentuate the biggest challenge facing Joe Paterno's team during the spring -- namely, finding a new starting quarterback.
Beyond confirming what most already assumed -- that the first-team QB derby has been narrowed to sophomore Kevin Newsome and redshirt sophomore Matt McGloin -- Saturday's action reinforced the idea that the battle will continue through the spring and most likely into the preseason.
As the second-teamer behind Clark last season, Newsome figured to have an edge over McGloin this spring. But other than being the first quarterback to see snaps with the first team Saturday, Newsome did little to distinguish himself.
He was extremely erratic during Drill 6 (7 on 7), overthrowing or under-throwing nearly every pass. He opened the actual scrimmage by leading the first-team offense against the first-team defense, hitting on only 1 of 4 passes but also scrambling for a first down on a drive that eventually stalled.
Later, leading the second-team offense against the first-team defense, he fumbled a snap (but recovered) and then missed wideout Brett Brackett. Facing third and 16 from his own 29, he made his best play of the day, avoiding the blitz and scrambling for 26 yards.
He followed that with a quick strike to tight end Garry Gilliam and later hit tight end Brennan Coakley to the 2-yard line. Newsome then ran option, pitching to early-enrollee tailback Silas Redd for a 2-yard TD.
Newsome finished the day 3 of 9 for 38 yards, no scores and no picks.
McGloin nearly gained more yardage on his first pass. Leading the second-team offense against the second-team defense, he fired a bomb to reshirt freshman wideout Shawney Kersey, who made a sprawling catch for a 34-yard gain. McGloin was 5 of 9 for 56 yards on the drive, which ended on Collin Wagner's 34-yard field goal.
Later, McGloin led the first-team offense vs. the second-team defense and was even more effective. He completed his first two passes, both to senior wideout Graham Zug, for a total of 57 yards. He finished the day 8 of 17 for 118 yards, no scores and no TDs.
It should be noted that McGloin did not face the first-team defense Saturday.
Paul Jones, the rookie who enrolled in January with the hope of fighting for the starting job, saw limited action Saturday. He had one series with the third-team offense (against the No. 3 defense) but spent most of his time handing off.
The other area of concern for the PSU offense this spring is the line. The top three tackles from last season are gone, including All-Big Ten pick Dennis Landolt. To adjust, the staff has been tinkering with different combinations all spring, and Saturday's first-team was a complete overhaul from the line that took the field last season.
All-Big Ten center Stefen Wisniewski has been moved to right guard. Lou Eliades, the returning starter at right guard, is now playing right tackle. Fifth-year senior Doug Klopacz is manning the center spot, while former tackle DeOn'tae Pannell is at left guard and former guard Quinn Barham is at right tackle.
To recap, the new line looks like this: RT, Eliades; RG, Wisniewski; C, Klopacz; LG, Pannell; LT, Barham.
Former starting guard Johnnie Troutman has been busted down to the second team.
Because of that new look, the first-team defensive line generally pushed around the offensive front. On a fourth-and-1 early on, tailback Stephfon Green was thrown for a 2-yard loss. The first-team offense did find the end zone once against the top defense, though. Late in the hour-and-a-half scrimmage, the offense put together a short-field march on the legs of Redd and redshirt freshman power back Curtis Dukes.
Following a nice gain by Dukes, Paterno laid into the defense, showing emotion for the first time on the day. It didn't rally the troops, though, as Dukes muscled into the end zone from nine yards out three plays later.
The only other scores in the game were a pair of 1-yard TD blasts by fullback Michael Zordich, one with the third-team offense and one with the second-team offense.
Veteran tailback Evan Royster dressed and warmed up but did not play in the scrimmage, presumably because he does not need the experience. Green saw very limited action.
Redd, Dukes, transfer Hykeem Brodie and walk-on Derek Day saw the bulk of the carries and all looked good. Redd showed outstanding quickness and vision, while Brodie ran with power.
Outside of the shakeup on the offensive line, there were really no shockers among the starting offense or defense. Led by Zug, Derek Moye and Curtis Drake, five different wideouts worked with the first-team offense. Andrew Szczerba is the new starting tight end.
On defense, the rebuilt linebacker corps featured Chris Colasanti in the middle, with Bani Gbadyu and Nate Stupar on either side of him. Mike Mauti, who is recovering from an ACL tear, dressed and took part in individual drills but did not engage in any contact.
Chaz Powell, who moved from wideout to cornerback, was running with the second team Saturday.
This was Penn State's eighth practice of the spring. The Lions will practice 15 times in all, culminating with the April 24 Blue-White Game.
No players or coaches were made available interviews following the scrimmage.