Celtic manager Neil Lennon admits his team suffered from a lack of belief as they crashed out of the Europa League in emphatic fashion in Utrecht on Thursday night.
Lennon would have been relatively confident taking a 2-0 lead to Holland but the Glasgow giants were left reeling when that lead was wiped out in the space of seven devastating minutes as Ricky van Wolfswinkel converted twice from the penalty spot. He then completed his hat-trick early in the second half before substitute Barry Maguire completed the 4-0 rout.
"It didn't look like we believed we could get a goal," said Lennon. "We made changes to try and rectify it with Shaun Maloney and Ki Sung-yeung and Paddy McCourt coming on to try and have more attacking flair because the initial formation obviously didn't work."
He added: "But it didn't matter what sort of personnel we tried to make, it didn't look like we were ever going to score. We didn't put the keeper under any pressure whatsoever."
Celtic have now won just once away from home in Europe in 28 matches but Lennon insisted: "You can't go on about history and our record in Europe because it's a different manager, different team.
"But we still make the same mistakes away from home and it has to be a mentality thing because they are the same players as last week.
"Ball retention, defending at times, second balls. I've said to them I watched Chelsea play Wigan and they were quite prepared to put their bodies on the line and block things and put their foot in.
"I'm not just saying that about the back four, it was endemic through the whole team. We backed out of challenges and didn't want to close people down.
"I will have to look at the overall performance and see where we went wrong. We have to improve quickly because this will be a sore one for me for a while personally."