This is from CBS, Trapasso which is a rather poor source, but I think this may be the thinking after the combine
especially if Key runs a 4.65 or better.
4. Arden Key, DE, LSU
His electric burst and bend are apparent -- maybe he's finally fully healthy and conditioned? -- and his length and power are impossible to miss. Per Pro Football Focus, Key has 18 quarterback pressures (three sacks, four hits, 11 hurries) on 80 pass-rushing snaps in his last three games, including seven (one hit, six hurries) against Alabama. Yes, Key jumped from out of the top 20 to No. 4 because he's that naturally talented.
Trapasso ranks Chubb #5. I wouldn't go that far. I'd rather have Chubb.
But because of his speed and his combination of pass rushing moves,
Arden Key is probably the best pure pass-rusher in the draft.
My guess is that Key will weigh close to 270 for the combine.