Jablonec will face "hell" when they walk out against Celtic next week, according to boss Petr Rada.
The Czech side have a mountain to climb in the second leg, having been 4-2 by Ange Postecoglou 's side in the home tie.
Though the away goals rule is no longer in force, Jablonec would have to win by two clear goals just to take the Europa League qualifying tie to extra-time.
And that task will be even harder with a full house allowed at Celtic Park for the return.
Rada is expecting a torrid night in Glasgow, as he told his players they must show no fear of the raucous crowd.
He said: "The tie is now all about our players not being too frightened next week.
"If you don't play European football every season and have played a season without any fans and suddenly 60,000 supporters come to your match, it's not going to be easy.
"The prospect is giving me even more wrinkles on my head.
"Celtic fans are famous, they sell their stadium out for every match. It will be hell.
"At half time I told the players that if they continued to play as they did in the first half, they would be thrashed.
"I think losing by only a goal would have been acceptable, but the fourth goal was a terrible one to lose for us.
"So it's up to us to go to Glasgow next week and adapt to what is a difficult position for us."
