Ange Postecoglou is looking for a self-help European response from his Celtic players following the 6-2 friendly defeat by West Ham at Parkhead on Saturday.
The chastening defeat by the Hammers – notwithstanding two teams of Hoops players were used over the 90 minutes – was not the preparation the Celtic boss wanted for the second leg of the Champion League qualifier against Midtjylland on Wednesday night, with the score tied at 1-1 from the first game in Glasgow.
Postecoglou told CelticTV: "We have got three or four days and it is as much about the players as it is about us.
"My job is continually work with them and the staff working with them to give them the tools they need.
"It is about them as well. It is about them growing and understanding what they can and can't do on a football field, what approach they need to take.
"It will be as much about their response as it is about me giving them guidance moving forward."
The sunny afternoon in Glasgow in front of around 18,500 fans started well for Celtic.
Skipper Callum McGregor curled in the opener in the seventh minute but the complexion changed after West Ham striker Michail Antonio scored a quickfire double and captain Mark Noble netted from the spot.
Ryan Christie pulled a goal back five minutes after the break but goals from Said Benrahma, Jarrod Bowen and Armstrong Okoflex, signed from the Parkhead club this summer, gave a none too pretty look to the scoreline for Celtic.
Former Australia boss Postecoglou said: "I think there were some positives but certainly some areas that were very disappointing.
"We didn't really take the opportunity to test ourselves against a quality opponent and I guess that is the biggest disappointment, that we kind of shied away from a little bit of a challenge.
"We started brightly, created some good chances, scored a goal and then we just seem to make a mistake and collapse as a unit, rather than get a response.
"Mistakes are going to happen but again, the reaction to it wasn't great."