Glenavon manager Gary Hamilton slammed James Taylor following the goalkeeper's "moment of madness" against Coleraine.
Taylor was sent off after clashing with Coleraine goalscorer Kirk McLaughlin as the striker attempted to retrieve the ball from the back of the net.
Referee Tim Marshall initially brandished a yellow card before producing a red after consulting with his assistant.
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Glenavon held on to claim a 3-2 win, despite having to play the final 14 minutes with striker Matthew Fitzpatrick in goals.
Hamilton fumed at Taylor after the match, with the keeper facing a six-match ban for his actions at the Showgrounds.
"We had a moment of madness from our goalkeeper," Hamilton told BBC Sportsound.
"I'm not happy about it and there are no excuses for it. And he's been told I am not happy about it.
"Now he's missing for six games through stupidity. And now we're without our number one goalkeeper for the five games in the split. And if we're fortunate enough to reach the play-off, he will be out for the first game of that as well.
"It's not good enough and it is not acceptable from your number one goalkeeper to do stuff like that. It is crazy.
"I am not happy. I thought he really let the players down today, and there were 12 or 13 minutes left after that and he made it a really difficult 13 minutes for his teammates."
Glenavon held on for an important win that keeps them in seventh spot in the Premiership, and occupying the final European play-off spot with five games left.
They currently sit just one point above Ballymena United who beat Larne on Friday night.
Hamilton added: "Fitzy (Matthew Fitzpatrick) came in and made a really good save and we hit Coleraine on the counter a couple of times with 10 men. We could even have scored another goal.
"Credit to the lads. I asked them for a win today. They showed their character and determination."
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