‘Knox’s roster spot is obviously safe, but it would be good to have him work with Josh Allen between now and Week 1 of the regular season. Croom, however, is very much on the roster bubble thanks to the emergence of seventh round pick Tommy Sweeney. If the Bills decide to carry four tight ends at the start of the year, Croom could claim the last spot if Kroft starts the regular season on the PUP list.’