Hull were charged with failing to control their players following a 68th-minute incident in which they surrounded referee Jonathan Moss after Alex Bruce was booked for his challenge on the Leicester winger.
Tom Huddlestone’s sending-off in the same fixture means the former Tottenham man will be suspended for the visit of Chelsea on Sunday.
But ahead of the Premier League clash with Mourinho???s side, who were also accused of badgering the referee during their Champions League match at home to Paris Saint-Germain recently, Bruce says Mahrez’s alleged offence is more serious.
Bruce said: “I’ve got the highest respect for Mahrez but the way he rolled around the pitch is something which for me we’ve got to stamp out because I think that’s what incenses all of us.
“The frustration was that he was blatantly trying to get somebody sent off. We surrounded the referee because it was a perfectly fair challenge and we will vigorously defend it.
“I’m not saying the reaction of the players (was right), but there was an injustice and the one thing we have to stamp out more than anything is players rolling around faking injuries.”
Hull are currently three points clear of the relegation zone, but Bruce insists his club will be taking nothing for granted.
Bruce admits the Tigers may not achieve their target at the beginning of the season of 10 wins, yet feels his side have another quality in their squad to survive.
“I have said from day one, 10 wins is usually enough. Looking at the table, I am not going to be far short of that.
“It might be nine, it might even be eight, but whatever it is, whatever target you need, thankfully over the last six games we???ve picked up nine points which is terrific for us. It has got us out of the bottom three and given us a bit of daylight.
“Over the next nine games can we repeat that? If we repeat that, it is going to be very difficult for teams below us to match that.”