It is one of the small details of the very complex problems that Ledley King has with his knees that he is unable to join his five-year-old son for a kickabout. He is the footballer who does not train, has missed large swathes of games through injury and, despite being one of the most talented defenders of his generation, is only now playing in his first World Cup finals.
But, at the age of 29, the Tottenham Hotspur captain now bears, in large part, the hopes of the England team on his broad shoulders. The saddest sight of yesterday was Rio Ferdinand coming down to watch training on his crutches and no one is better placed to understand Ferdinand's plight than King. For once though, King is not the injury story of the week. Instead, he is the rescue act.
The Spurs man is the favourite to step into Ferdinand's position in today's friendly against the Platinum Stars, the North West province's South Africa Absa Premiership team, and then on Saturday in England's first group game against the United States. Today is three years since he last partnered John Terry in the middle of England's defence against Estonia in a Euro 2008 qualifier.
The two defenders, who played together as kids at the famous Senrab boys' club in Wanstead have started together in the centre of defence for England only five times and naturally there are concerns about King's readiness. "What I can guarantee is that I will give 100 per cent and I'm ready to play if needs be," he said yesterday. "I feel I can perform at the highest level.
"I don't necessarily enjoy the work I have to do in the gym but as a professional I have to do that to be able to play matches and I love football. That is what has kept me going.
"It would be a dream [to play at a World Cup], I am here as part of the 23, just the same as every player, working hard to prove I can be part of a winning team."
The work in question is very different and means King is unable to train with the rest of his team-mates other than during warm-ups. At Tottenham, this is an accepted part of their captain's regime but, having never been part of one of Capello's squads before now, there was some trepidation on King's part as to how his manager would accept this unusual arrangement.
King said: "It's difficult for him and me coming into this situation. I felt awkward at first but I couldn't have asked for more. He's been brilliant. It's just a different situation. Before the squad met up I had not been involved with England [under Capello] and they've not seen how I work. It's been a bit of a shock to the players and maybe the staff but the manager has been brilliant.
"He has told me to do what I would normally do. There are times when you're tempted to try to do a bit too much but I have to try to make sure I'm available and ready for games. There have been other times when I've had chats with him [Capello] and asked when he wanted me on the pitch, if there were certain days he needed me other than the day before a game.
"He's not a manager who is going to show favouritism to anyone. You have to perform and do the right things. It was flattering that he showed great faith in me. It's great for me to have that much respect from somebody of his magnitude, a manager who has been there and done it all. I'm hopeful I can repay that."
King has little to no cartilage in his left knee, which means that, as Harry Redknapp is fond of saying, it swells like a balloon after the exertions of a game. He had a major operation on it after those England games he played three summers ago and the best he can say about it now is that the problem is not getting any worse. His outrageously bad luck meant he missed the last World Cup because of a broken metatarsal.
"You are a long time retired, so you might as well do everything you can now," King said. "That's the way I look at it. A footballer's career is short and I'm trying to get as much out of it as I can. No player really knows when their time is going to end, so I'm trying to concentrate on doing as much as I can.
"My knee is something that affects me every day, even in the summer. It's part of my body, it's something I have to deal with. Every time I get up and walk, there are restrictions with it. I can't stretch my knee up to stretch my groin. I can't grab hold of my knee in that way. My son loves football and there are plenty of times when he's trying to get me out in the garden or in the park to play and it can be tough.
"I think he's heard enough about my knee to know there's some kind of a problem. As a kid you can't really understand it, but it's something he's heard over the last few years. It's difficult as a dad to see you can't play."
As for his partnership with Terry, King says he knows enough about his Chelsea counterpart to be confident they can play together. He has spent so many years observing a stand-in play his role in training ground set-pieces that he has no fears of playing in a relatively new partnership. Both of them favour the left side of central defence and King said he would be the one shifted to the right.
"It's difficult but I've watched enough of John for years and I've played with him and know his game," King said. "Communication is key for defenders. He's a big talker and I will talk and I'm sure we'll be fine. I've seen enough of John and know him well enough. If it's a player you don't know well then looking at a few videos might come in handy but it's not like that in this case.
"It doesn't worry me. John Terry is a top-class centre-half. We played for Senrab together. He was a midfielder then and he used to shout at us even back then. He was only a small kid, a lot shorter than now, but he had great leadership qualities. He played in front of me and I think he was the captain. Paul Konchesky, Bobby Zamora and Kamal Izzet were in that team.
"John was the same in midfield as he is at the back really. He was courageous, throwing himself about – doing things that us young lads hadn't really seen before."
In the search for parallel careers to his own, King cites Paul McGrath, the Manchester United and Aston Villa defender who suffered similarly debilitating knee problems and rarely trained. He says that he has read McGrath's confessional memoir, Back from the Brink, although the Irish international had more problems than just his knees. Apart from a well-publicised contretemps with a Soho doorman, King has managed to keep the demons at bay.
He gives credit to Nathan Gardiner, a Spurs physio who has taken charge of his treatment since the last major operation and accompanied him to the Austrian training camp last month. King said: "He knows me well enough to know when to push and when to ease off. It's something we've developed. First of all he's got a great appetite for his job and as a player that's what you want and respect – someone who will give you a nudge when you don't want to do certain things.
"He has given up a lot of time and effort for me to be able to play. He came out to Austria with me and the team when he could have been on holiday with his family. I gave him my shirt after the Mexico game just to thank him. He's an important person to me. I've been working with him since I had my operation three years ago, the big one, and since then really we've been together."
King played at Euro 2004 against France but had to return home on the morning of the game against Portugal for the birth of his son Coby, who came nine weeks premature. This is a man who has had more than one unexpected obstacle thrown into his path and who is hoping that this time around nothing will prevent him from at last playing at a World Cup finals.