THERE is an inevitability about Celtic winning the title, but there is, too, an intrigue about their prospects in the William Hill Scottish Cup.

The Clydesdale Bank Premier League remains unsecured, at least arithmetically, but that is a technicality that will be resolved when league football reconvenes after the break for the cup semi-finals, where Celtic meet Dundee United at Hampden on Sunday.

The mere mention of the national stadium will provoke a wince in Celtic supporters as recent defeats to such as Ross County, Hearts, Kilmarnock and St Mirren in the south side of Glasgow have wrecked deeply held hopes of cup triumph. Neil Lennon has been bitterly disappointed at these failures, and Mikael Lustig, in the wake of a facile defeat of a supine Hibernian, quietly acknowledged that Celtic's recent record at Hampden had to be changed.

One difficulty is that the champions have been strolling to a title and now have to up the pace. "It can be hard," said the 26-year-old Swede of the imperative to play with razor-sharp focus next week after an afternoon when Pat Fenlon's side allowed Celtic to win while playing with some restraint. "We have struggled before at Hampden and I know the lads want to show that we're a really good team and we can perform well, even at Hampden. We want to show people we can win there."

This ambition will be helped if Kris Commons, who was substituted possibly as a precaution after taking a knock to the ankle injured at St Mirren Park last week, and James Forrest, dogged by the effects of a back injury, can play at Hampden. Forrest will return to training this week and Lennon will hope both his protege and Commons can reprise the form that makes Celtic a dynamic force. Forrest supplies pace and crosses, while Commons has an uncommon craft.

He scored two goals on Saturday, should have had a hat trick and was integral to most of the enterprising play by the champions. Lennon praised his front two of Gary Hooper and Anthony Stokes for their ability to link well and find space, but his ruffling of Commons' hair as the Scottish internationalist left the field was possibly the most telling verdict on an afternoon when Celtic were not troubled defensively and when goals came with a slickness of play by the hosts and a slackness on behalf of the visitors.

Celtic had quickness of thought in attack, an untested resilience in defence and an energetic, clever and committed performance by Joe Ledley in midfield. It was Commons, though, who caught the eye.

Lustig had no knowledge of his team-mate when he arrived at the club in January last year, but three months later he watched as Commons provided evidence of his capabilities in a 3-0 victory over Rangers. The defender believes his colleague is returning to that sort of devastating form. "Especially over the last few games, he's been really good. He's been really important to us," he said.

Celtic domestically face teams whose first priority is to defend then counterattack. "You need players like Kris and James Forrest, guys who can take the ball and do something special," said Lustig.

He conceded that the body shape of Commons, who sometimes seems as if he is had been dipped in shorts rather than measured for them, had caused unfair criticism. "It's like Hoops [Gary Hooper]. They're really fast players. You see them in training, they're really quick over a few metres. Of course they're not like the best over 200 metres. But this is football and we saw in the game how important Kris is."

He added: "If you train with him every day then you see the quality he has. His left foot is probably the best in the league." He said, too, that Commons was probably the best technical player in the league and an influential force off the pitch, as well.

Lustig, whose preference is a home game with Motherwell as a potential title decider as the first post-split fixture, was involved in some controversy when Celtic's third goal came off his hand. The Swede did not celebrate but the goal was awarded after referee John Beaton looked to his assistant and was presumably not informed of any wrongdoing.

"I felt the ball went to the hand," admitted Lustig. "I did what I did then it was up to the referee. Sometimes you know you're offside but you score anyway. I won't celebrate it if I know it touched my hand but I think it's then up to the referee. I thought the referee would disallow it, it was a clear handball." Lustig's hands out, non-celebration was, he said, by way of apology to the Hibs players.

His thoughts then moved to the cup semi-final. There is a determination that the sorry results at Hampden are consigned to the past. The league race is all but over but a test awaits Celtic both physically and psychologically at the national stadium.