4. Marcus Mariota
Mariota barely saw the field for the Las Vegas Raiders in 2021 as Derek Carr’s backup, with two pass attempts, 13 rushing attempts (for 87 yards and a touchdown) on 24 total snaps. His last extensive action came late in the 2020 season when Carr was sidelined by an injury during a game, as he completed 17 of 28 passes for 226 yards with a touchdown and an interception along with 88 rushing yards and a touchdown on nine carries.
Mariota may have his eye on being able to compete for a starting job somewhere (Steelers, Broncos?, Browns?), and that kind of opportunity is at least less clearly available in Detroit. But on the idea general manager Brad Holmes might consider adding legit competition to the mix, Mariota could see Jared Goff as a vulnerable starter he can beat out if allowed the chance to.