EVERY manager has his own unique way of dealing with the job.

In Ronny Deila's case, it appears compartmentalising is at the root of his modus operandi.

Having ended what he considered to be Part One of Celtic's season - which comprised the chase for a spot in the Champions League along with the start of their defence of the SPFL title - he has taken time to reflect on the good and the bad which it threw up.

"We play a lot of matches, and there have been some compromises in the first two months of the season because of Champions League and things," mused the manager.

"But, I have said to the players, 'We are ready now to go into the second chapter of our season'."

With the international break over, normal service in the championship resumed with a 2-1 win over Aberdeen, and their opening Europa League group game against Red Bull Salzburg coming up on Thursday, Part Two is well and truly up and running.

It could prove to be a challenging one, though nowhere near as season-defining as the first, given how important qualification for the Champions League is to any campaign and set of accounts, as the healthy figures released last week underlined.

Toss in a tough League Cup opener against Hearts to add to the mix of Thursday/ Sunday action from now until December, and it's certainly not going to be a period when anyone at the club can kick back and take a rest.

Well, not voluntarily, at any rate.

As Saturday confirmed, however, the intake of new players, finally completed as the transfer window was closing means that, every match day, a clutch of unhappy Bhoys are going to find themselves sitting in the stands, reduced to the role of spectator.

For the match against Aberdeen, Leigh Griffiths, Derk Boerrigter, Jo Inge Berget and Liam Henderson found themselves on the outside looking in, while Anthony Stokes fared only slightly better as an unused sub.

When James Forrest, Mikael Lustig, Charlie Mulgrew, Adam Matthews and Darnell Fisher recover from their respective injuries, starting places will be at even more of a premium - which is precisely the competitive situation Deila is seeking to create.

Any manager arriving at a club needs this to ensure the transition he aims to push through can succeed.

If players are comfortable in the mindset that they can't be left out because the manager has no viable alternative, a subconscious resistance towards getting with the programme can prevail.

Any such danger has been averted by the activity in the transfer window, with the arrival of men like Stefan Scepovic and John Guidetti, both of whom made their debuts at the weekend.

Aleksander Tonev also finally took his bow, though it appears he made more of an impression on Dons full-back Shaleum Logan than on anyone watching from the stands.

The SFA will investigate allegations he made racist remarks towards his opponent during the first half which saw Celtic take the lead through an Efe Ambrose shot which flew into the net off Jason Denayer.

Celtic doubled their lead within seconds of the restart when a Kris Commons shot went off off the boot of the unfortunate Logan.

But the Hoops were made to sweat for all three points - and their first win in five games - after poor defending allowed David Goodwillie to head past Craig Gordon, who had already made a clutch of good saves and went on to make even more as Aberdeen pushed for an equaliser.

Fortunately for Celtic, they were able to hold out, and Deila believes the improved fitness levels they can now draw upon was a major factor in achieving this.

He is confident that, the fitter his Bhoys become, the more capable they will be to deliver to the level he demands.

"If you can't run, then you have no chance to perform how you need to," is his basic philosophy.

"Football is a running game, and we need to be quick and sharp for 90 minutes. Games and professionalism, on and off the pitch, plus good training is what will bring this level of fitness."

Deila continued: "I am very satisfied with the players just now. We just need to work on making the changes I want, not in too quick a way, because there is a lot to learn. That's a very important thing, to get people in the right fitness condition."

Despite the fact the majority of the starting XI had been on international duty while many Dons player had been able to enjoy some time off, Celtic did appear to have a spring in their step from the opening whistle.

The high pressing game and quick passing which is at the core of what Deila wants from them is designed not to allow opponents to settle.

However, playing at a high tempo has to come naturally. If it is forced, it leads to misplaced passes and bad decision-making.

Deila is also very big on energy being shown, and returning skipper, Scott Brown, certainly led the way as he scampered all over the pitch like a Duracell bunny.

Again, though, this energy from lesser-super-charged team-mates has to be expended the right way, or else it is wasted and runs out before it can make the game safe.

Fortunately for the Hoops, the back line has stamina and pace in abundance, the latter an important antidote to the errors which are still being made too often.

Deila still considers it very much a work in progress, and is happy that they have regained their wining thread.

However, he did concede it should have been a more comfortable afternoon.

"There were spells in the first half which were of a very high level and you could see the potential in this team," he said. "But, we should kill the game."

That will be the order if they can get their noses in front in Salzburg on Thursday as Part Two of the Euro season kicks into gear.