Sunderland manager Gus Poyet has claimed that he is unsure about the referee's decision to send off Wes Brown in the Black Cats' 2-0 defeat away at Manchester United on Saturday.
In the second half at Old Trafford, John O'Shea appeared to tug Radamel Falcao to the ground in the Sunderland box, with Brown arriving on the scene to muscle in.
Referee Roger East, however, ruled that the latter was the main culprit, showing him the red card despite protests by both players.
Poyet told BBC Sport after the game: "It was difficult to see what happened - we're trying to get a video. It's between two players. We have to analyse. It didn't look an easy decision to make.
"The referee said that Wes Brown was the one who fouled Falcao first. That's what he told the players. You need to ask the referee [about the decision]. We will analyse it and make a decision."
The defeat sees Sunderland remain 16th in the Premier League table.