Phillip Cocu was understandably an angry man after Derby County saw their recent unbeaten run come to an abrupt end at Luton Town on Tuesday evening.
Derby fell to a 3-2 defeat at Kenilworth Road against the Hatters, with all five goals coming in the second half of the Sky Bet Championship encounter.
Wayne Rooney curled in from the edge of the box to open his account for the club to give the Rams the lead just after the hour mark.
Luton turned the game on its head after goals from Pelly-Ruddock Mpanzu and Donervon Daniels, before substitute Chris Martin equalised with a header from Jayden Bogle’s right-wing cross.
However, a late Bogle own goal ended the Hatters' eight-match winless streak, before defender Max Lowe was sent off soon afterwards.
Derby went into the game unbeaten in seven in all competitions and Cocu felt the Rams threw away a real opportunity to keep momentum on their side.
Speaking to RamsTV, Cocu said: “The loss was really unnecessary and that is why I am very angry and upset about, giving this game away in such a bad way.
“We dominated the game and as it went on we played better and better and we deserved the goal to give us the lead.
“We got the goal and from that moment, we got a warning with a good save from Ben Hamer, we were totally gone. Two set-pieces cost us. In the first set piece we were reacting, we were not in the right position and that was a key moment because they got energy from it.
“Another set piece soon afterwards saw us go behind and we had to fight back.
“We still played our football, scored a great goal to make it 2-2 but then we lose the game. It is impossible that we lose the game when you score such a late equaliser and then concede the third goal in such a childish way.”
He added: “A good streak and a positive run ends and that really was not necessary.”
Cocu was in particular unhappy with the way Derby managed the game from the moment Rooney opened the scoring.
Derby had displayed a marked improvement in that area in recent weeks, as well as defending set-pieces.
However, Cocu admitted his side only had themselves to blame for the manner in what they lost the game.
He said: “We went 1-0 up, but they took control of the game.
“We were out of position when before that we were loyal to positions, we had very good control of the ball.
“When you go ahead you want to do well. Maybe they took a few more chances, played a little bit more direct but still you have to know and switch on after a goal to keep control.
“We didn’t do that. If you get a set-piece when you are not in a good position to react on the second ball, then that is our own fault. We have to blame ourselves in that part of the game.”
The Derby boss also admitted there was a real sense of frustration in the dressing room after the final whistle.
He said: “There is frustration in the dressing room and so there should be with the result.