Celtic skipper Scott Brown believes team spirit can reverse a three-goal deficit against Legia Warsaw.
The injured Bhoys captain will be in the dressing room beforehand calling on his team-mates to show the same spirit and belief that pulled them out of a similar hole last season.
Ronny Deila suffered a difficult start to his Celtic career when the manager lost Brown to a torn hamstring literally seconds into his opening pre-season game.
And the pressure intensified when Celtic capitulated in Poland last week, seeing Efe Ambrose sent off in a 4-1 defeat in their Champions League third qualifying round first leg encounter.
Legia also missed two penalties, and whether that merely saved Celtic from utter humiliation on the night, or whether it ultimately rescued their Champions League hopes, will become clear at Murrayfield tomorrow night.
Celtic suffered another painful European defeat last season, in the fourth qualifying round against Shakhter Karagandy, but Brown and his colleagues recovered to overturn a 2-0 defeat at Parkhead.
And the midfielder had an instant response when asked what the key to their comeback was.
"Spirit," he said. "Everyone believed we could do it. We knew we were a better team than we showed over there and I'm sure the lads will be thinking that as well.
"We have a point to prove. Can we go out and do it again? I believe we can.
"It always hurts when people write you off, but that's football. People always write you off. That's when you have to put the wrongs right and go out there and show everyone what you can do.
"You can prove a point to everyone out there on the field."
Brown is making progress from his injury but still looks likely to be out until October, which could rule him out of Scotland's Euro 2016 qualifiers against Georgia and Poland in the middle of the month as well as the September visit to Germany.
"It's getting there slowly," he said. "It's a good three-month injury, that's for sure. But I started jogging today.
"Definitely September I'll be hard-pushed to make and we will see about the other ones."
Team news for Legia Warsaw clash
Ambrose is suspended for the second leg of Celtic's Champions League third-round qualifier against Legia Warsaw at Murrayfield.
The Nigeria defender was sent off in last week's 4-1 defeat in Poland which left group-stage aspirations up in the air.
Skipper Scott Brown and James Forrest remain out of contention with long-term injuries.
Celtic squad: Forster, Matthews, Izaguirre, Van Dijk, Mulgrew, Lustig, Commons, Johansen, Biton, Kayal, Boeriggter, Berget, McGregor, Stokes, Griffiths, Pukki, Balde, Henderson, Zaluska, Gordon, O'Connell.