Manchester United boss Louis van Gaal labels Wayne Rooney's red card as a "professional fault".
The Englishman was shown a straight red after kicking Stewart Downing and will miss home games against Everton and Chelsea and a tricky away game against West Bromwich Albion after the international break.
"I think we have played very good in the first half, very attacking, attractive football," van Gaal told Sky Sports.
"We conceded a goal from a corner, which is a pity because we were playing very good. I said at half-time I was pleased.
"Then you get our set-play, the break from West Ham and the right card for Wayne and that changed everything.
"I think that the referee could give a red card. I think he [Rooney] did it too unfriendly, because you can do it in a more friendly way. I call that a professional fault.
The Red Devils survived a late scare to hang on to a 2-1 win with the Dutchman full of praise for debutant Paddy McNair.
"We have the problem we don't have the height of the West Ham United players and they were playing the long ball, so it is very difficult to hold this result, but I am very happy we have done that," added van Gaal.
"I am very happy that we have won because it is important for a player who is making his debut, and I thought that he [Paddy McNair] was very good. I am very pleased for him."
