Shaun Treeby has received a three-week suspension for his dangerous tackle on Piers Francis at Newlands.
The incident took place in the 47th minute of Friday night's match, which the hosts won 30-22.
The Blues flyhalf was knocked unconscious as a result of the blow, but Treeby was only penalised for the tackle, with no card – yellow or red – being issued.
The Sanzaar foul play review committee accepted a guilty plea from the Stormers centre.
In his finding, committee chairman Nigel Hampton QC ruled the following:
'Having conducted a detailed review of all the available evidence, including all camera angles and additional evidence, as well as an explanation from the player and submissions from his legal representative, Thembelani Mayosi, the foul play review committee upheld the citing under Law 10.4(e)”
'With respect to sanction the foul play review committee deemed the act of foul play merited a mid-range entry point of six weeks. However, taking into account mitigating factors including the player's excellent judicial record over a long professional career and his early guilty plea the foul play review committee reduced the suspension to three weeks.
'The player is therefore suspended for three weeks, up to and including the Saturday, 10 June 2017.'