Ange Postecoglou wants Celtic to take their Europa League disappointment out on Aberdeen on Sunday.
The Hoops lost 4-0 to Bundesliga outfit Bayer Leverkusen at Parkhead on Thursday night to leave them bottom of Group G along with Ferencvaros, without a point in two games.
Celtic have now won only twice in their last eight matches in all competitions.
The former Australia boss was frustrated by aspects of their performance against the in-form Germans and wants to see improvement against the Dons in the cinch Premiership.
Postecoglou said: “It is not about lifting them.
“You have to take this disappointment and let it fuel you.
“It is not just about being a good football team, there’s got to be something more there and we disappointed our fans on Thursday night.
“You have to take that anger and that disappointment and use it in a positive way and that is in a tough game away from home, show that we have learned the repercussions and consequences of a night like Thursday night and we don’t want to repeat it.”
Postecoglou was glad to see captain Callum McGregor return from a hamstring problem for the match against Leverkusen and believes he is the man to help Celtic get firing again against a struggling Aberdeen side who have also gone eight games without a win.
He said: “You don’t want to ignore your opponent because you want to respect what they bring.
“They have had a probably disappointing start for them so I guess they will be just as motivated and they didn’t have a game in midweek so they may see some advantage in that.
“But again, all these things become irrelevant, we just have to be a stronger team than we are at the moment.
“In terms of turning our performances into results, getting Cal back will help because he is one that won’t accept what is going on at the moment.
“If you look at that starting line-up, there is a lot of guys who are just starting their Celtic careers and having someone like Cal out there to make them understand what is expected at this football club in terms of consistent performances and consistent results, I think will help us in a game like Sunday.”