Depends on when the Bills want to start the clock. Don’t they have 21 days to use or lose him once he starts practicing?
“Once a player leaves the reserve/PUP list, he has up to 21 days to return to the 53-man roster. He can practice with the team until he’s taken off the list. If the player still isn’t able to play in games after the 21-day span, he’ll stay on the reserve/PUP list for the rest of the season.”