Watford manager Gianfranco Zola says he was baffled by the decision to send-off Matej Vydra during his side's 2-1 home defeat by Middlesbrough.
Vydra was dismissed two minutes before half-time following a second yellow card, with referee Steve Rushton believing the striker had stamped on Nicky Bailey.
The Hornets went ahead in the first minute through Troy Deeney, before Marvin Emnes levelled matters for Boro after half-an-hour.
Scott McDonald grabbed the winner on 77 and Zola said: "I understand the referee can see something but a good indication for the referee is the reaction of the players.
"No one in there did anything. It was just that the man (Bailey) was in front of him, he (Vydra) tried to jump over him and then he touched but you will see."
As for the result, he added: "I don't think we deserved that and especially today because my team was playing very good football and created a lot of chances.
"We allowed them to come back. Middlesbrough is a good team and they scored but we thought we still had the game in control. But after that episode (the sending-off) it was another story."