Bristol have lost their appeal against captain Siale Piutau's three-match ban.
Piutau and Worcester's Andrew Kitchener were both suspended after accepting charges of striking an opponent during last Friday's Premiership match.
Bears coach Pat Lam has said he was "extremely frustrated" by the suspension, claiming Piutau only acted in self defence.
However, an online disciplinary panel on Thursday said the "maximum mitigation" had already been applied.
The panel ruled that Tonga centre Piutau should have been facing a mandatory minimum ban of six weeks for "any act of foul play which results in contact with the head".
And they dismissed the appeal as the maximum mitigation of 50%, resulting in a three-match suspension, had already been granted.
Piutau, who was sin-binned following the incident in the 79th minute of the game, while Kitchener was shown a red card, will be free to play again on 20 September.
He has already missed Tuesday's Premiership victory over Northampton and will now also sit out Sunday's game his old club Wasps - Bristol's play-off rivals - and also next week's European Challenge Cup quarter-final with Newport Gwent Dragons.
Lam told BT Sport after the Worcester game: "You should be able to defend yourself if someone attacks you like that.
"Siale was attacked by two guys who started swinging at him."