RONNY DEILA spent last night watching Scotland lock horns with England at Celtic Park.

But the Norwegian student of the game was not able to focus fully on trying to understand the unique tribalism associated with this reunion of football's Auldest Enemies.

The Hoops boss was keeping an eye and an ear open for any news on the 15 Celtic players who have been away on international duty over the past 10 days.

It is always a fraught time for a club boss as he waits to welcome back his men, hoping they return only with good memories and not injuries.

But with a clutch of crucial games on the immediate horizon, this final international hiatus of 2014 has left Deila more anxious than usual.

Red Bull Salzburg come to Glasgow a week tomorrow, a night when Celtic can get the points they need to join the Austrian champions in qualifying for the Europa League last 32.

Just three days after that key game in Group D, the Hoops head to Tynecastle for their Scottish Cup clash with Championship leaders Hearts.

Deila has reiterated his determination to become the first Celtic boss since Martin O'Neill to secure a domestic Treble.

But having already lost in the League Cup to the Hoops, he knows the Jambos will be fired up for revenge in this tie.

The league programme is also unrelenting in the run-up to the festive season, with Celtic finally able to play their game in hand from the start of the campaign, the Glasgow derby against Partick Thistle, the following midweek.

Eight days later, they are off to Croatia to play Dinamo Zagreb in the final Europa League group stage tie, a match which could yet determine if they have European football in the spring.

It's going to be a hectic end to what has already been a roller-coaster year of transition for the club.

Deila hopes to be able to go into these games with as many big names as possible fit and playing their part.

The return to action after three months out of James Forrest as they defeated Aberdeen before the shutdown was a huge boost for the club.

Another big-game hunter, Kris Commons, is hopeful he will be ready to join the squad for this weekend's resumption of action against Dundee.

But while the break for internationals has given the walking wounded more time to regain their fitness, there is already collateral damage from battles around Europe and beyond.

Mikael Lustig was clearly in distress when he limped off at half-time in Sweden's Euro qualifier against Montengro.

The initial reports are the full-back has suffered more hamstring trouble, the severity of which is already being assessed by the Celtic medical staff.

It would be a huge blow to Lustig if he is faced with yet another enforced lay-off.

This time last year he accepted he had to go under the knife for surgery on both his hips, forcing him to sit out four months of the season.

He has also been marked absent for several weeks earlier in this campaign, and it was no coincidence his return to action, at Dingwall a month ago, coincided with Celtic hitting their most consistent run of form since Deila took charge.

However, one man's misfortune looks like being another's long-awaited opportunity.

Efe Ambrose has cut a forlorn figure sitting on the bench in recent weeks.

The Nigerian's last appearance in the Hoops was in the shock home defeat to Hamilton on October 5.

Jason Denayer has replaced him at centre-back. He found another role at right-back, but that ended when Lustig and Adam Matthews returned from their injuries.

With Ambrose helping Nigeria get back on course to defend their Africa Cup of Nations title in January and February with a 2-0 win over Congo on Saturday, the defender knows he needs regular games to retain his place in the Super Eagles team.

This has led to questions being asked regarding his long-term future at Parkhead, though the 26-year-old insists he is willing to stay and fight for his place.

Ambrose said: "I'm still a Celtic player and I'm happy there. If it's time to move, I will. But for now I remain a Celtic player."