Clifford tallied 15 receptions for 266 yards and a touchdown last season as a redshirt junior.
The annual scrimmage kicks off at 2 p.m. in Beaver Stadium.
Granville made an appearance in seven games as a true freshman.
Mupoyi was the 40th-ranked edge rusher and No. 2 overall recruit in Connecticut in the 2023 recruiting class.
"Penn State afforded me the opportunity with people that took an interest in me, afforded me the opportunity to have a wonderful life and career."
Robinson played in 14 games in 2024 making 11 tackles.