CELTIC boss Ronny Deila has warned his players they cannot afford a repeat of their sloppy display in the 5-3 defeat to Dukla Prague in their Champions League qualifier later this month.
A strong Hoops side, with skipper Scott Brown playing the entire game, were behind for most of the friendly at St Mirren Park with Czech ace Marek Hanousek netting a hat-trick.
And Deila has told his team they need to step up against Icelandic champions Stjarnan in the second qualifying round a week on Wednesday.
When asked what watching Stjarnan boss Runar Pall Sigmundsson would have made of his side’s performance, the Norwegian replied: “I think he saw some possibilities there.
“We can’t play like this or we will get big problems whoever we play, if it’s against Stjarnan or St Johnstone or Barcelona.
“It was a good test for us. They are a good team.
“I don’t think we had a good performance, but it’s early. We have been back four days with 60 per cent of the team.”
Deila started with Dedryck Boyata and Charlie Mulgrew in central defence, while new right-back Saidy Janko was on the bench.
The Norwegian said: “Defensively, we have good players, it’s not about the quality, we just have to be sharper. We were always half a second too late.
“It’s frustrating to watch, but you just have to swallow and look forward to the next training session and match.”
The Hoops take on David Moyes’ Real Sociedad on Friday at St Mirren Park.