Neil Lennon hurt by 4-0 loss
Lennon would have been relatively confident of progressing to the group stages after goals from Efrain Juarez and Georgios Samaras in the first leg at Parkhead provided what appeared to be a comfortable advantage ahead of the clash in 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.
He added: "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."