"The trouble is you need to beat him with a big stick to keep him away from training at times, such is his enthusiasm to do his bit for us, " observed Gordon Strachan last week. At this time of year the manager has every reason to be grateful that such doughty characters occupy the Parkhead dressing room.

The title race may effectively be over, but there is no hiding the wear and tear on the Celtic squad as they prepare for the rush of festive fixtures.

Last weekend's Old Firm game only added to the walking wounded. Mark Wilson injured knee ligaments and faces weeks on the sidelines, while fellow full-back Lee Naylor suffered a badly gashed ankle.

McManus, meanwhile, already has the air of a grizzled veteran and is only 24.

He had to pass a late fitness test to be involved at Ibrox.

Yet you can be sure he will grin and bear his pain again on St. Stephen's Day to ensure he retains his place in the starting line-up as Dundee United travel to the east end of Glasgow.

"Honestly, it's not as big a thing as everyone makes out.

I just need to keep on top of the problem, but I should be fine. It is a wee thing that comes and goes, but it is not a big deal, " said the centrehalf dismissively.

"I keep training the way I have always trained. Maybe there is a day or two when you come in feeling sore and cannot train, but it is just one of those things. That's life. It is what being a footballer is all about. You'll certainly not hear any of us complaining - you just get on with it."

He insists he is not stupid enough to risk exacerbating the problem should the injury become more serious, but dealing with discomfort is part of his job. "I think it is just something inside you, " he said, explaining his mentality. "When you have worked so hard to get some place, you don't want to give it up easily. Someone could come into the team and do well and then I'd be sitting on the sidelines. And I have sat out for long enough in the past so I'm not interested in doing that again."

McManus has learned that lesson the hard way. It is just over two years since an enthusiastic attempt to retain possession saw him slam into an advertising hoarding at Livingston. The collision split open his right knee, keeping him out for three months just as he was starting to establish himself in Martin O'Neill's side.

This season, under Strachan, it is Bobo Balde who has struggled to regain his place, as McManus and Gary Caldwell developed an impressive partnership. A knee injury has now forced Caldwell out of the equation, but McManus knows there is little time for sympathy.

Steven Pressley, the former Hearts captain, could yet arrive in the January transfer window to provide the manager with greater options at the back, but the young man who quit school early to sign for Celtic has no intention of giving up his place to anyone, regardless of experience or reputation.

"It doesn't bother me who I'm playing next to as long as it is me playing week in, week out. You need to be selfish at times that way and look after yourself. Bobo is a good player to have around, but even he appreciates that you cannot expect to go straight into the team, whether you are a new player coming in or a player who has been out injured, " he said.

"Myself and Gary were doing well and then Gary picked up an injury and Bobo came in. It is unfortunate, but that's football. I think I'm in because I deserve to be there.

I've cemented my place, which is great, but it is important you don't take it for granted because you still need to work hard and be professional and perform every time you go on the pitch because, if you are not performing, you'll not be in the side, " he added.

Given their healthy lead at the top of the SPL table, it would perhaps be understandable if some Celtic players saw the advantage of first-footing slightly gingerly into the New Year.

But all McManus senses is the same relentless drive.

Last season, Strachan's side picked up maximum points from the five games between St Stephen's Day and 22 January, and it would go against the grain for his players not to demand the same from themselves again.

That determination has been evident during several dust-ups between teammates this season, with Aiden McGeady, Neil Lennon, Artur Boruc and McManus all involved in on-pitch altercations at some stage or another. McManus, who exchanged a few choice words with the Celtic captain during the Champions League match at Old Trafford, simply points to the league table and suggests such fighting spirit hasn't done them any harm.

"We've got a lot of powerful characters, a lot of folk who will speak their minds and I think that is something that makes the team so strong as well, " he claimed.

He feels, after long years battling from schoolboy forms to Celtic starter, he has earned a right to have a say.

"I've been a first team player here now pushing five years.

In fact, I'm probably the one who has been here the longest. I left school when I was 15 and came straight here. That was 1998. I think I've got as much right as anybody else to be talking. And that comes with responsibility too."

Tomorrow, after training, he will spend the rest of Christmas Day dashing between his girlfriend's parents and his own. "We're not any different from any other family - we're just normal down-to-earth folk, " he observed.

Except while most of us enjoy a break over Christmas, McManus will not let up his focus or give in to his discomfort. Not with his place in the Celtic team at stake.