Slavisa Jokanovic felt Ryan Fredericks' red card changed the outcome in Fulham's 1-0 defeat at Birmingham.
The full back was dismissed for a late lunge on Craig Gardner which led to a furious reaction from the home players. Lukas Jutkiewicz scored the only goal of the game soon after.
Fulham were not at their best but Jokanovic was not going to complain about his side's effort.
He told BBC Radio London: “It's disappointing but we didn't play our best game. We had many problems during the game. They were solid and won the second balls. We didn't create so many chances.
“The situation with Ryan Fredericks killed us in one very complicated moment for us where we tried to push and win the game.
“The situation was a real setback. I can't complain about the effort of my team but we didn't play our most brilliant game.”
Jokanovic refused to criticise referee Andrew Madley, responding by saying: “Ask me something different. I prefer not to answer.”
The defeat is a setback to Fulham's play-off hopes but Jokanovic will take it one game at a time.
He explained: “It's not over. Generally, we had a setback. We're disappointed but there are 51 points in front of us.
“We have to take it step by step and get ready for the Wigan game. I don't know what'll happen in the end.
“Our target is similar for the end of the season but I prefer thinking about the present and the next game.
“The competition is not over. We have to push hard and be competitive and try and win the next game.”
