Fleming spent one year at Penn State after playing four years with Ohio State.
Izzard's deal is worth $2,655,000 with $225,000 guaranteed.
Wormley anchored the right guard position for the Nittany Lions last season, starting all 16 games.
Nelson made an appearance in all 16 of Penn State's game in 2024.
Clifford tallied 15 receptions for 266 yards and a touchdown last season as a redshirt junior.
The two signal callers played the majority of reps in Penn State's spring game as they vie for the backup quarterback job.