Emre Can branded Liverpool "stupid" after defeat to Crystal Palace.
The German midfielder admits their top four hopes are again in doubt after the Anfield reverse.
"We are frustrated and disappointed," Can said.
"We controlled the game. I think we didn't play too bad but then we conceded two goals from two chances.
"Everyone is very disappointed because we should have won this game. We had the chances.
"It was stupid from us. Again it was a set-piece. We had worked on them in training, we had trained very well.
"In all the set-pieces in training we had done very well, but again we concede a goal from a set-piece. It was stupid."
He also told liverpoolfc.com: "We miss a lot of our players, there are a lot of injuries. You should look at Chelsea. They are lucky with that for example.
"We don't have luck with this. But it is no excuse. We have to go again. We have to fight for our target. From Monday, we have to look forward."