My rule use of thumb.....
3 QB
4 RB/FB
6 WR
3 TE
8 OL
24 offense
8 DL
6 LB
9 DB
23 on defense
K, P, LS
3 special teamers
50 roster spits
the 3 extra would fill in fir short term injured players or young rookie picks, ir other raw talent you fear won’t get to PS
if AJ injury is a 6 week injury then buffalo likely has a 4th QB on the roster
The other 2 spots
1 on offense between RB, TE, WRm and IL
1 on defense would be between a LB and DB