THE PERFORMANCE Stephen McManus and Gary Caldwell delivered against Manchester United was an unadulterated thrill for everyone at Celtic, with the possible exception of four men. When the United circus had moved on and the rush of excitement began to fade, the reality was sobering for Glenn Loovens, Darren O'Dea, Bobo Balde and, stuck away down in Norwich, the loaned out John Kennedy. McManus and Caldwell had never looked more immovable, never looked more embedded, never looked more secure as the bedrock of the defence. Happy news for Celtic, dispiriting for the men hopeful of taking over from them.

Not since Willie Miller and Alex McLeish last patrolled together in 1990 has there been a Scottish central defensive partnership with the potential to operate side-by-side for several years at club and international level. McManus and Caldwell, both 26, are in their third season together with Celtic and, since George Burley took over, they have been the default partnership for Scotland. Burley has likened them to Miller and McLeish. In fact neither is as individually impressive as the Aberdeen pair were, but the partnership is evolving and improving. Caldwell, in particular, has been excellent this season. Many thought him too prone to mistakes and he was loudly criticised, but he has responded with form which has earned him a new contract offer.

Miller was at Parkhead to provide analysis for Radio Scotland last Wednesday and when he later reflected at length on McManus and Caldwell his praise was unrestrained. "Look at the quality of the opposition - United were exceptional in the first half and world class in the second - yet Celtic still managed to keep them out all bar that one goal. Their positional sense was fabulous. Their understanding with each other throughout the game was first class. The two centre backs, being under that much pressure, stood up to the challenge and came out of it with honour.

"Playing together is important. After maybe a decade together it was almost telepathic between myself and Alex. He knew what I was going to do and I knew what he was going to do. Stephen and Gary have had their telling times and their critics. It's a measure of the character that Caldwell has shown that he has come through bits of that.

"Individually they are both good players and they have grown in stature. Games like that one are only going to help them. You get landmark games in your career that give you the belief that you can go on to bigger things. Myself and Alex had it playing for Scotland at Wembley in 1981, we had it against Bayern Munich in 1983. These kind of games just give you the belief to kick on and go on to better things. They are at a perfect age, their peak athletic years are coming up and they are mentally improving. They can play a bit as well, they're not just big stoppers. They show composure too. Maybe on the night I thought United's corner kicks caused them a problem or two. That was the only weak part of their game."

One spectator with a vested interest saw something else to concern him: the ball. Artur Boruc will undergo a knee operation tomorrow which is likely to mean Mark Brown continues in goal for Celtic's penultimate Group E game away to Aalborg on November 25. That will require him to deal with a ball he described as "ridiculous" because of its unpredictable movement. The official Champions League ball, the Adidas Teamgeist, has been criticised by some for being too light. In Brown's opinion it was the unpredictability of the ball's flight which deceived Boruc on Wednesday when he could only parry Cristiano Ronaldo's vicious shot into the path of Ryan Giggs, whose header cancelled out Scott McDonald's opening goal.

"Honestly, having trained with those balls, they are ridiculous and should be banned," said Brown, who played a Champions League tie against Spartak Moscow last season. "The way the ball moves is incredible. It's like nothing I have ever seen. At the time I thought Artur's save was a great one because I know how much that ball moves. I sympathise with him, especially with the way Ronaldo kicks the ball. It is completely different to the SPL ball made by Mitre. It is so light that even trying to curl the ball is next to impossible. Even outfield players don't like it because passing the thing is a lottery.

"The first time we used it, before the Aalborg home game, we were out training and I was thinking oh my God, what's this?' Adidas won't be happy with my comments. They are trying to make it lighter all the time but it's too light."

Qualification for the last 16 remains theoretically possible for Celtic but there has been an inclination - not from Gordon Strachan or his players - to regard the three points from the Aalborg trip as being in the bank already. In fact, if Celtic lose that away game, and of course they tend to experience nothing except defeat on their travels, they will finish bottom of the group and be out of Europe altogether. A draw would mean they could finish no higher than third. A win would prolong their prospects so long as Villarreal and Manchester United do not carve up a draw on the same night, as a point would be enough for both of them. Even a cursory glance at the group table suggests the damage has been done. It is asking too much to hope that sides of United and Villarreal's calibre might throw away a six-point advantage with two games left.

The strength of the English and Spanish representatives, the injuries to Jan Vennegoor of Hesselink and Georgios Samaras and the concession of two points at home to the Danes have brought Celtic to the brink of elimination. They have scored only once and taken just two points from two home matches when in every previous season those pair of fixtures have yielded six.

The pleasure Strachan derived from coping with United at all was unmistakable. The defence's triumph had been his, too, because his bold decision to play two in attack helped to occupy United and relieve a little of the pressure on his players. "Looking at it, we were actually far more comfortable when we put two strikers on the pitch. The two strikers were dragging Man United people back to defend. In the second half we only had one after Cillian Sheridan tired and had to be withdrawn in the 63rd minute. So then United could loiter up the pitch and keep themselves fresh and when the ball came to them they could take off. So defensively, Scott and Cillian did very well for us."

Long after Miller had put down his microphone on Wednesday night a listener called the station to complain that Celtic had been just as guilty of "anti-football" as Rangers were when attracting criticism in their 4-5-1 slog towards last season's Uefa Cup final. Presumably the caller felt it would be sensible to play three up front against the holders of the European Cup.

Celtic's manager did not share that enthusiasm for tactical suicide. Going with two was brave enough, and he was rewarded with a performance from his defence which he described as the best since he came to the club three-and-a-half years ago.