Fabregas was sent off for kicking a ball at West Brom midfielder Chris Brunt, as the referee tried to diffuse a confrontation between Diego Costa and Gareth McAuley.
Tony Pulis??? side, who were already ahead through Saido Berahino???s early strike, went on to win the game 3-0, and Mourinho told Monday Night Football he thought the decision was wrong.
???With experienced referees, stable, big personality, in control of the game, I think [they use] words,??? he said.
???Especially in a game where you play for nothing, and when it was just nothing special, it was a ball without any aggression, I think one of the top referees would resolve the problem with words.
???But Michael decided to give a red card, which I disagree with completely, but he???s the referee.???
Costa was also at the centre of attention on his return to the side, as he clashed with the West Brom players throughout the game.
The striker was booked for the fracas involving McAuley, but Mourinho insisted he is not getting enough protection from referees.
???You have to speak more about the opponents than him,??? he added.
???If you see what the opponents did to him from the first minute, I think it???s easy to understand there are other people to mean.
???If the referee wants to protect the talent and to punish the bully, it???s easy for him.???
With the title already secured, the Blues boss felt his side lost motivation for Monday night???s clash ??? something he also said he was guilty of.
Chelsea host Sunderland on the final day, live on Sky 1, in a game which could prove crucial in the battle to avoid relegation, but Mourinho wanted to assure the teams involved his side will be trying to win.
???I know my players, I know myself, I know the nature of the game ??? I know what normally happens when a team is champion with matches to play,??? he said.
???When we are champions so early it???s difficult to keep the motivation high. We have lots of injuries, we have players we are protecting.
???The motivation is not so high, the intensity is not so high, and when you lose that salt and pepper of the competition it???s difficult to compete at the highest level.
???I cannot be critical of my players, because to be fair it was also my mentality. I cannot blame them without blaming myself.
???The ideal scenario is to be champion and go home and you don???t play again. If you blame somebody, you have to blame Man City, Man Utd, Arsenal and Liverpool because they let us win the title so early.
???In the last match, if other teams are waiting for us ??? if Sunderland need the game, if Hull City or Newcastle need the game ??? I think we are going to feel that responsibility. Hopefully we can perform different than we did today.???