The Nittany Lions completed the largest comeback in program history on Saturday, defeating Army 7-6.
Cain spent 2019 to 2021 in Happy Valley before transferring to LSU.
Driver, who has three years of eligibility remaining, entered the transfer portal on December 5.
The Nittany Lions fell in overtime before dominating game two.
The secondary was the Nittany Lions' biggest Achilles' heel in Atlanta.
The Rebels put up 394 yards and three touchdowns through the air against the Nittany Lions.