Saracens prop Josh Ibuanokpe has been banned for five weeks after accepting a charge of "striking with the head" against his former side Harlequins.
Saturday's incident involving ex-England captain Chris Robshaw came in the second half of Sarries' 28-21 Premiership Rugby Cup win on Saturday.
A Rugby Football Union disciplinary panel agreed contact was not deliberate and cut the maximum ban by 50%.
Ibuanokpe's "clear disciplinary record" was taken into account.
Chairperson Matthew Weaver added: "The player was remorseful for the impact of his action and apologised. The club spoke of the positive impression he had made on the club since joining."
Ibuanokpe is free to play from Tuesday, 19 November.