• Spurs defender hopes knee won't hinder his progress
• 'To be here is something I will never forget,' says King

The return of Ledley King to prominence is a heart-warming tale that tempts supporters to ignore any little shiver they feel over a defender whose damaged knee has a fame of its own. Fabio Capello looks likely to turn to him for England's opening World Cup match with the USA on Saturday now that Rio Ferdinand is ruled out of the tournament by a relatively mundane knee problem.

It is the measure of King's excellence that the England manager, regardless of medical issues, has always wanted to pick a centre-half whose positional play he admires. The hole in the cartilage of the player's right knee does not stop him from plugging gaps in a back four. Capello has been unusually excited to see King appearing more regularly.

"No player can guarantee their fitness," the defender said. "What I can guarantee is that I will give 100% and I'm ready to play if need be. I feel I can perform at the highest level." It has been pleasing to see the re-emergence of the 29-year-old, who received his first cap since June 2007 in the friendly with Mexico last month.

King scored and was replaced at the interval. The defender, by his own admission, did not have a good game, yet Capello sought proof of his condition, not of his talent.

He was not risked at all in the latest friendly, against Japan. He is frank about the restrictions: "I can't stretch [bend] my knee up to stretch my groin."

It is a triumph for King still to be a professional footballer, let alone one who is so admired. He sets out the severity of the problem in a touching manner when talking of his five-year-old son, Coby. "He loves football first of all," King said, "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."

Participation of any sort is subject to rationing. Coby was born prematurely on the day of England's Euro 2004 quarter-final with Portugal and King left the squad before kick-off. A metatarsal injury kept him out of the World Cup two years later, but Capello seems to have decided that his moment has come.

King and John Terry, his expected partner in defence, have a shared background since both were once with the renowned boys club Senrab. "He was a midfielder," King recalled, "and he used to shout at us all even back then. He was only small, a lot shorter than now, but he had great leadership qualities."

It would be sentimental to assume that the two players will dovetail at the World Cup because of that connection and they have been in harness from kick-off only six times for their country since the first occasion in 2004, against Ukraine. King is confident even if there is little rehearsal on the training ground.

"I've watched enough of John for years and I've played with him and know his game," the Tottenham Hotspur player said. "Communication is key for defenders. He's a big talker and I will talk, and I'm sure we'll be fine."

Exaggeration over the state of his knee is discouraged. "I've had scans going back over the last two or three years and it's not really got any worse," King said. "It's nice to know that it's in a similar situation to when I had the operation [in 2007], if not a bit better."

The Tottenham physio, Nathan Gardener, appears to have come up with a programme that manages the knee more effectively than before and the player presented him with his shirt following the Mexico match. "He knows me well enough to know when to push and when to ease off," King said.

"First of all he has got a great appetite for his job and as a player that's what you want. You 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 [the England camp] in Austria when he could have been on holiday with his family."

Capello leaves well alone. "He's told me to do what I would normally do," King said. "There are times when you're tempted to do a bit too much but I have to try to make sure I'm available and ready for games."

King has been hindered in his career and is yet to appear in the Champions League, so it is a fulfilment for him to be readying himself for the World Cup finals.

"To be here is something I will never forget," he said. "A career is short. No player really knows when their time is going to end, so I'm trying to concentrate on doing as much as I can. That's why I don't do too much training – because I see the games as the most important thing."

King has certainly been assimilated into the World Cup scene and offers the now ritual remarks about the unpredictable movement of any new ball that is developed for the tournament. "We will see a lot of that," he said, "and it will be different for strikers as well, not just for goalkeepers."

King thus joined the ranks of many well-known grumblers. If the knee does not affect him, he can prove that this exalted level is where he truly belongs.