RONNY DEILA claims playing at Pittodrie on the back of a midweek European away tie represents the biggest test yet of his players' mentality.

But the Celtic boss is confident the work being done to provide the required toughness is starting to show through.

"It will be the toughest game and maybe the most 'funny' one as well," he said, cryptically, as he looked ahead to tomorrow's lunchtime kick-off.

"It's going to be a full house and I feel we're ready for it."

Deila and his backroom staff, in particular Jim McGuiness, are putting huge effort into developing the mental stength of their charges.

But the manager insists it really has to come from within.

He said: "The players have to be their own psychologists, and I have to be a very good one.

"But it's important to have a team around you that gives you input and the chance to reflect on things and that's going to help us win matches.

"The mentality of the team now is very strong.

"I said on the very first day we need 11 players who work defensively and offensively as well.

"On Thursday against Astra you saw that, and that's why we are getting points away from home.

"We fight and we need to win challenges, but also we need skill to have a passing pattern.

"In the first half we showed we were dangerous and produced good moments.

"I think if we'd kept on going we'd have scored more goals.

"But also remember that is three times now we've gone up in games away from home in Europe and have let the lead go.

"We need it to be otherwise the next time."