RONNY DEILA has made great play of the fact Celtic can't rely simply on two men.

The Hoops boss was referring to skipper, Scott Brown, and last season's top scorer, Kris Commons, who combined to win and convert the penalty which gave the Parkhead club a point against Motherwell at the weekend.

Both players had initially been left on the bench as Deila had, once again, rung the changes as he attempted to juggle domestic and European commitments.

The manager believes it is necessary to rest his Bhoys to keep them at the highest level of performance and fitness possible, both long term and short term.

However, there is one player who he is happy to select every week, Callum McGregor.

In fact, the 21-year-old attacking midfielder is the only Celt who has appeared in every one of their 13 games across three different competitions this season.

The only match McGregor did not start was when Deila made wholesale changes for their visit to Inverness a month ago today.

Even then, the Hoops boss felt compelled to throw him into action at half-time as his team needed an injection of pace, accurate passing and goal threat.

It is huge testimony to how integral McGregor has become to the team that he is one of the first names Deila puts down when selecting his starting XI, whatever the game or the opposition.

The kid who spent last season on loan at Notts County honing his skills and developing the maturity to make the step up to first-team football at Celtic has used the opportunity given to him by Deila as a stepping stone to move on up into the Scotland squad.

And, though he was a unused sub for the Euro 2016 qualifier against Germany earlier this month, Gordon Strachan was so impressed by the way he carried himself among the squad that he is ready to retain McGregor in his group for the next double-header, against Georgia and Poland.

Deila has brought in seven players since arriving as manager, but considers McGregor to be the eighth new signing -and one he is extremely grateful to have at his disposal.

That's confirmed by his continued selection of the youngster.

And, while most kids who make the breakthrough struggle to retain their place as form in developing players is notoriously difficult to maintain, McGregor is proving the exception to the rule.

He's not quite a freak of nature, but is certainly proving to be an exceptional young man, and Deila is unstinting in his praise for the grounded kid who has set his own bar so high.

The manager said: "Callum can take a lot of matches.

"And, in the wide position where he plays, that has been important because we don't have so many players who can do that job.

"James Forrest is still out and now so is Derk Boerrigter, while Wakaso Mubarak has got an ankle injury.

"So that is another reason Callum is in the team so much.

"But, as I said, I think he can handle that number of games."

It is not just McGregor's physical durability which has allowed him to play an important role in all the games played by Celtic this season, and which will keep him in contention for a starting place against Hearts when the Hoops begin their challenge for the League Cup tomorrow night.

He has an old head on young shoulders, fits the cultural profile which Deila demands in terms of being a 24-hour-a-day footballer, and has proved to be a sponge for the knowledge the new manager is attempting to impart on his charges.

Asked if it is a sign of his maturity that he can sustain such a high level of performance in his first season as a first team player at Celtic, where demands are as great mentally as they are physically, Deila answered: "I think so.

"You saw again on Sunday that he was able to keep going and in the second half against Motherwell.

"He created a lot of chances for himself and for team-mates, which was important for us as we tried to get the equaliser then winner."

Width and pace are two essential components in the style of football Deila is seeking to deliver.

But the continued absence of Forrest - who is at least another three weeks away from a possible comeback - and the failure of Aleksander Tonev or Jo Inge Berget to hit the ground running at any discernable speed, matching the lack of impact made by the now-injured Boerrgiter, means the manager has had to adapt his system.

Wakaso showed when he made his debut in Salzburg that he can bring some balance and threat on the left side of the team.

He took over from McGregor as the wide man who can get forward and score vital away goals in Europe with a strike which marks the Ghanaian winger down as a player who can get fans up out of their seats.

But the exertions in Austria ruled Wakaso out at the weekend with an ankle injury, and he now faces a race against time to be ready to return against Hearts.

The loss of the width and pace which all these men bring to combat frustrates Deila.

But the manager knows he has to be patient, and said: "We know that we will eventually get the players we need for these positions back available.

"But it is also important that the players we do have every day work hard on getting better movement down the sides of our team."

Seeing this particular light at the end of the tunnel is one of the reasons that Deila is not being spooked by the run of results which has seen the Hoops win just one of their last seven matches.

He insists there is no semblance of panic and is confident they are going the right way.

"Of course I believe that," said Deila. "I think we have put in some good performances in the last few games."