Diving into the five-year grades for every off-ball linebacker with 1,500-plus defensive snaps since 2014, Mosley’s 78.6 overall grade ranks 16th and his 87.0 run-defense grade ranks sixth among the 89 qualifiers. The concern is the replaceability (and therefore lack of value) of strong run defense and his lackluster coverage ability, as he ranks just 24th on the aforementioned list in coverage grade (73.8) and has earned a 73.0-plus single-season coverage grade just once in his career.
Mosley tied for 151st among qualifying defenders in PFF’s WAR (Wins Above Replacement) metric at 0.34 in 2018, and he tied for 25th among all off-ball linebackers; better coverage linebackers (i.