Training grounds are a touchy subject with Roy Keane. It was the hard pitch at Ireland's 2002 World Cup camp on the Pacific island of Saipan which prompted that infamous row with Mick McCarthy, so his former nemesis must have had a quiet smile when he heard that the Manchester United captain was moving to Celtic.
Celtic Park is a 60,000-seat arena which most clubs in Europe would envy, but the club's Barrowfield training ground, just a quarter of a mile away has barely changed since McCarthy was pulling on green and white hoops in 1988. Indeed, it is much the same place where Jock Stein trained the players who won the European Cup in 1967.
In the old days, local vandals from the toughest housing scheme in Glasgow regularly broke in and set fire to the pitches. These days, the turf is like a bowling green, but only because of the security fences that would not look out of place at Alcatraz. Yet, this unlikely environment has put a smile on Keane's face, according to Gordon Strachan.
Celtic's manager has spent the last three weeks working with the Irishman at Barrowfield because the 34-year-old was not eligible to play until this weekend. Today Keane makes his debut away to Clyde in the Scottish Cup third round.
Far from being irritated by being kept on ice, Keane has simply warmed to his new life. "He seems to be more relaxed on the training field that's for sure," said Strachan. "Roy used to get uptight too often. Now he is far more relaxed with himself as a footballer. He knows what he's good at and what he's not good at. He's good fun with the lads."
That verdict was endorsed by Paul Lawson, one of Celtic's young midfielders who will watch from the bench today as Keane sets out to vindicate his decision to opt for Barrowfield over the Bernabeu. "There was an aura about him to start with," admits Lawson. "When he came it was a bit of a shock, especially as Real Madrid wanted him to start with, but he's just one of the lads now. He has looked ready to play from day one and it's just brilliant the way he conducts himself in training."
It was not just Real Madrid who were disappointed by Keane's decision to join Celtic. Several Premierships side were too, and Strachan even trod on the toes of one of his own former Manchester United colleagues to win the race for Keane.
"I was speaking to Bryan Robson yesterday and he said 'what are you giving him, we were offering him fortunes?' I said we had a joker up our sleeves in that Roy just wanted to come here."
Broadwood, of course, is hardly the summit of Keane's ambitions for Celtic, nor Strachan's. There is the small matter of the Scottish Premier League title and Europe, where Keane sealed his Celtic love affair by going to watch the 2003 Uefa Cup final. Whether he will still be pulling on his boots when Celtic move to a new £7m training centre in 2007 is debatable, but Strachan, who played top-flight football until he was 40, has no doubts about his recruit's longevity.
"I first came up against Roy when I was still at Leeds and he was at Nottingham Forest and I knew then that he was a good player," Strachan recalled of that brush 15 years ago. "He might have lost a bit of pace but I could see the same body language this week. He stepped up a level.
"Roy is like Gary McAllister. If there's five people watching a practice match in training they want all five to go away and say they saw a right good player. Roystill wants to be the best player on the training field."
Keane admirers will not be confined to the travelling support, they will also be in the home dugout at Broadwood. Joe Miller is the assistant to Graham Roberts, the Clyde manager, and still playing at 38, but the winger remains as fanatical about Celtic as he was when he scored the winner for them in the 1989 Scottish Cup final against Rangers.
"I think Keane will be a great signing," said Miller. "I flew from Australia to Seville just to be at the Uefa Cup final. That is what the club means to us. These days, I only come off the bench for the last 30 minutes and I don't want to miss this of all days."