Franklin added that there isn't anything stopping Carter from playing.
Mack was considered one of the Nittany Lions' best rising prospects after his one year in Happy Valley.
Clifford stepped down from his role effective January 2 to pursue other opportunities, according to a university release.
The Nittany Lions most recently beat the Fighting Irish 31-10 in the first full Beaver Stadium White Out.
"I'm a believer. I wasn't a believer in Penn State early on. I'm a believer right now."
Barkley will finish the season 101 yards short of breaking Eric Dickerson's record of 2,105 set in 1984.