Johansen's push up the pitch is giving Celtic forward momentum

But the Celtic manager is delighted to have been given so much food for thought by his fellow-Norwegian.

His dilemma is to choose where to field the 23-year-old midfielder to get the best out of him, and out of the team.

If anyone knows the answer, it is surely Deila.

He is the man responsible for plucking Johansen from the backwoods of football at Bodo/Glimt and developing him into a key member of the side at Stromsgodset which stunned Norwegian football by overcoming the odds to win the championship.

Johansen's performances were not only good enough to propel him into the national team, but also won him a £2million transfer to Celtic.

Since he arrived at Parkhead in January, he has picked up another league title.

But the player considered the ideal replacement for Joe

Ledley - after the Welshman's departure to Crystal Palace -saw his early form fluctuate as he moved around midfield.

Stints playing in a defensive role were mixed with spells out wide on the left.

When Deila arrived in June, the hope was that his history of working with Johansen would provide the catalyst for the player to push on.

That, quite literally, is what has happened as the player has moved further upfield.

In a more advanced position, his natural instincts to try to make things happen in a positive sense every time he gets possession are showing his qualities to their very best.

Not that it's been an instant transformation in Deila's 18 games in charge.

Like the Parkhead team in general, Johansen's progress this season has been a case of one step forward and one back as consistent form has eluded him and his colleagues.

But, pushed to the fore in the absence of Kris Commons on Saturday, the Norwegian was at the centre of all that was good about Celtic's powerful performance in their 5-0 demolition of Ross County.

He was instrumental in the Hoops' over-running of the Staggies as he helped to set up a couple of goals and was very unfortunate to see his own net-bound effort beat keeper Mark Brown only to be headed off the line by Scott Boyd.

Johansen was able to joke with County's central defender about his clearance as they left the field at half-time just a few minutes later. But it is Deila who has the biggest smile right now as he considers how well the wholehearted competitor has grasped the opportunity to finally show the form which encouraged Celtic to bring him across the North Sea.

The new manager believes this level of performance is the result of improved fitness.

And that gives him a touch of deja vu as Johansen himself is the first to admit it was his physical condition which held him back in Norway until

Deila got to work on him.

THE Hoops boss spent part of the international break watching Norway beat Malta then Bulgaria in the Euro 2016 qualifiers before his squad re-assembled for the trip to Dingwall.

And he is happy to confirm Johansen is not only turning it on for his club.

"Stefan has been fantastic in the last four games he's played with the national team," Deila said with no little pride. "He is now in the best shape I have seen him in for a long time. And that includes our time

together at Stromsgodset. He now seems more like the player I saw play for me there."

Deila believes that he may be in the fortunate position of being able to expect more from Johansen than Neil Lennon ever could while he was his boss because it was always

going to take the midfielder time to adjust to the move from Stromsgodset to Celtic.

"Stefan has been here for almost a year and he is now starting to settle down and

understand Scottish football," explained Deila.

"You can see that from his perfromances on the pitch."

Johansen has always been a willing runner and worker. But there is now a better and more consistent end product.

It is in the Norwegian's DNA to try to make every pass hurt the opposition.

When he has been playing in a deeper role alongside Scott Brown or Charlie Mulgrew in front of the back four, that has led to the loss of possession in dangerous areas.

However, when he is playing further up the pitch, as the middle man of three behind the striker, he knows if a pass does not reach its intended target then the damage, in terms of a turnover, is not as costly.

While, on the plus side, if

he does use his technique and

vision to thread a ball through the eye of an needle to a team-mate, it can wreak havoc in the opposition defence.

Johansen proved this to great effect on Saturday when he sent John Guidetti clear in behind the County backline before he cut the ball back for

Callum McGregor to score Celtic's second goal.

Then a driving run from the Norwegian ended with him laying the ball on a plate for Anthony Stokes to curl home the Hoops' third.

Allied to this creativity is a tremendous engine and work-rate which allows Johansen to get back to break down play whenever the opposition try to threaten.

That makes him a different proposition from Commons when invited to play in that advanced midfield role.

He is, though, unlikely to be as prolific as the 31-year-old Scotland international when it comes to scoring goals, with one this season to add to his two from last term.

DEILA now has to decide exactly where Johansen should play to show him

at his very best while also maintaining his team's goal threat and cohesion.

It is a conundrum that the manager is more than happy to wrestle with ahead of the match against Astra.

"That is a positive, not a problem," is his assessment of the dilemma that Johansen's versatility has thrown up.

"The midfield we started with on Saturday, with Scott and Charlie, is very strong."

All of which means finding a place for Commons, if he has recovered from his injury, may be the real headache for Deila.