THE evidence building suggests Ronny Deila is on the right track.

There were points during the early days of the Celtic manager's tenure when his methods and ideology were placed under severe scrutiny but of late any doubts over his suitability for the job have been largely extinguished.

Deila need only point at his team's record to counter any quibbles over the effectiveness of his managerial style; top of the Scottish Premiership with a game in hand, in good shape to reach the last 32 of the Europa League, awaiting a League Cup semi-final meeting with Rangers and a Scottish Cup tie against Hearts. Beyond qualifying for the Champions League, it is difficult to see what more Deila could have done in his first five months in the job.

Stefan Johansen is not surprised. Having worked under him at Stromsgodset, the midfielder was always confident his compatriot would deliver success to Celtic once he had settled at a new club in a strange country. Patience is a rare commodity in Scottish football but Johansen knew that it would take Deila some time to make the adjustments he felt necessary to get things operating to his satisfaction. The journey is not yet complete but Johansen feels things are moving in the right direction.

"At the start of season we didn't get the results we wanted," said the 23-year-old. "I said at that time, though, it was always going to take time with the new gaffer. He had new ideas he wanted to put into the team and now you're starting to see the team he wants. We are getting results and still in every cup while being at the top of the league.

"We're doing well in the Euro league as well and hopefully we can get through there. Things are starting to look good now but it's still early in the season and we need to keep it going. We want to win the two cups and the league. It's very difficult but it's still possible so that's what we're aiming for. I don't think any [of the players] had a problem sticking with him. He was talking to us all during that time. It's going to be good in the end. Celtic is going to be a success with him as a manager."

Any new arrival in Scottish football has their backstory forensically scrutinised before they have even set foot in the country. It was to his great embarrassment, then, that old footage emerged of Deila stripping to his underwear in front of the Stromsgodset fans - having just spared the team from relegation - prior to his unveiling as Celtic manager. That suggested he was something of a maverick, although there was little sign of any similarly eye-catching behaviour in his first few months in the job. Then came Celtic's recent late win away to Aberdeen when a pumped-up Deila celebrated exuberantly in front of the travelling fans before describing the moment as "orgasmic".

Johansen grins at the memory, and revealed there is a different side to the manager's ice-cool exterior that only appears now and then. "You can see the game meant a lot to him," he added. "Like everyone else at Celtic, he wants to be at the top of the table. With the way we won the game, with one man down, was great. It always takes time to adapt to a new culture but I think the gaffer is starting to get there. He's a serious guy when he needs to be but he'll also make some jokes.

'The important thing is he's got a good mix - in training we needed a hard session after coming back from the international break. But of course, sometimes he will make a joke or something. That's good. Sometimes you need to have a laugh. You can't be serious all the time."

It would be easy to imagine Johansen would come in for special treatment given he speaks the same language as the manager and worked with him previously. He is quick to deny that is the case. Just as John Guidetti was given a few pointers despite scoring a hat trick, so Johansen is still taken aside by Deila from time to time to point out where he could be doing better.

"He is always saying things to me because he always looks for improvement. He does that with all the players - especially when you are doing well. He wants you to do even better every day. I think that's how it should be."