The Nittany Lions' depth has been tested throughout the first two games of the season.
The first two games yielded inconsistent defensive results.
The Nittany Lions most recently played the Minutemen in a 63-0 win last season.
Barkley ran the ball 24 times for 109 yards during the win.
Rappleyea was ruled out of Saturday's game against Bowling Green.
Penn State's third-down percentage on offense and defense ranks 93rd and 89th, respectively.