Weatherspoon picked up a 15-yard penalty for roughing the passer on the first-quarter play. The rookie Manuel had to be taken out of the game for a snap and was replaced by backup Thad Lewis.
Players are typically fined $15,750 for such infractions.
Fellow Falcon William Moore also was flagged for unnecessary roughness against the Bills and could have received a fine. Moore was not available during Wednesday's open locker room session. His latest penalty came as a result of a high hit on Bills receiver Robert Woods.
Moore already has been fined a total of $74,550 -- according to NFL records -- for four separate illegal hits this season.