The Reds lost the game 1-0 at the DW Stadium, following a goal from Hugo Rodallega.
“We have to be really disappointed, after a defeat you always cannot be happy,” he told Sky Sports.
“In the first-half we didn’t do anything, (we were) giving the ball away, not winning any first or second balls.
“It’s difficult to explain. The second-half a much better attitude but it wasn’t enough.
“It’s difficult to explain. I think it’s a question of attitude in the first-half.
“I think that the players in the second-half showed character. I think sometimes we were playing too quick, but at least we showed character, in the first-half we didn’t play well.”
He added: “We have to keep going. We have an important game on Thursday (against Lille) and then we have to keep going, keep winning games if we can.
“We had some chances but we didn’t play well.”
