Celtic's increasing understanding of their manager's philosophy means they are going into this week's evocative meeting with Inter Milan more ready for European action than at any time this season according to their vastly experienced goal-keeper.

Craig Gordon finally conceded a goal for the first time in 816 minutes on Saturday and was forced to make an extraordinary double save to preserve Celtic's 100 per cent winning record in competitive matches in 2015 as they won 2-1 at St Johnstone, but he reckons their winning run reflects growing belief in Norwegian boss Ronnie Deila's methods.

"We have continued to build. We probably didn't have the best start to the campaign but as everything has started to settle in and the manager's ideas are coming across, things have improved and we look a stronger unit and a more formidable side," said the Scotland international.

"We have been continually chipping away at it. The manager works on it two or three times a week, the shape of the team and how he wants us to attack and to get back into position when we do lose the ball.

"I think we have started to grasp that now as a team and that shows with the amount of goals we have scored and the lack of goals we have been conceding. We are definitely heading in the right direction."

Deila's approach in seeking to change attitudes towards preparation and conditioning drew scepticism when he arrived in Scotland but Gordon - who has revived a career previously feared to be over since becoming the manager's first signing - trusts in the Celtic backroom to the extent that he was not even intending to watch Inter in action live yesterday as thoughts turned to their meeting with the Italian giants.

"We haven't looked at any video of them yet," he said.

"We have been concentrating on the games we've had here. The preparation will now start for that game and over the next few games we will be studying them and seeing how we can try to hurt them in different ways.

"I won't watch them on television. I'll get the coaches' report. They'll break the game down to the different situations that we may have to deal with and that is the way we will try to analyse it.

'You can overthink things and look for things that aren't there. It's better to let everybody do their jobs."

Celtic's greatest ever win may have been at Inter's expense but the fortunes of the two clubs and more particularly their national leagues in the intervening 38 years mean Thursday's visitors to Celtic Park are heavy favourites to triumph over two legs, but Gordon believes he and his team-mates can cope, while the home crowd can also lift them.

"Celtic have come across big names in football before and done very well," he observed.

"We know we will have to be at our best and a lot of people will have to be at the top of their game to get a result out of this one but that's a good challenge and one we are excited about and ready to go with.

"It is a sell-out which will be enjoyable in itself. The players will respond to that and hopefully get a big performance. It will need to be to try to get something."