Watford manager Walter Mazzarri felt Pereyra’s red card cost his side a point and the Italian blasted referee Graham Scott, believing his decisions played a big part in the outcome of the match.
Pereyra was sent off for reacting to a challenge from James McClean, who escaped with just a yellow card following a confrontation and skirmish involving players from both sides.
Mazzarri said: “I think it’s absolutely normal that a player gives a small push after a rival pushes him all the time. If someone has to be sent off then it has to be the other player. If not, then both should be sent off. It should never be like it was.
“The referee changed the result of the game. On the first goal (Watford goalkeeper Heurelho) Gomes was blocked. You can’t block the goalkeeper. If you do block the goalkeeper it is a foul. I am angry that we lost the game unfairly.
“The football was probably the best in an away game since I arrived at the club. We didn’t deserve to lose. We deserved something from the game.”
Pulis on the other hand was more concerned about trying to keep his player out of trouble.
He said: “It was right in front of me. I think the kid kicked out. I was more worried about James and trying to keep him away from it. You just don’t want your players to get involved – you don’t need it.”