There are lots of surprises about John Terry. One of them is that he has written training notes and coaching manuals since the first day Jose Mourinho took charge at Chelsea in 2004. They fill shelves of his study, along with replica trophies occupying more space than most Premier League boardrooms.

The books are studiously tidy and labelled and filled with scribbles and arrows, crosses and names, information, observations and revelations. There are hundreds of diagrams. I can't say I have ever seen anything like it.

Another surprise is that the last time I saw Terry socially in the summer, he was talking about retirement. So today we're meeting at his house near Chelsea's training ground, presumably to talk about the end of his career after a long summer in Portugal from which he has only just returned. He looks tanned and slim.

'I have the voice of Ray Wilkins, who was such a brilliant man to me, in my mind. He missed playing every day after he retired and he told me, "John, play as long as you can, don't close that door until you have to".'

For a moment his eyes moisten as he talks about his mentor Wilkins, who passed away in April. 'He was always the one who was first on the phone when something happened to me, good or bad. "Morning fella"… such a lovely man. I miss him so much.

'When I grew up and did my YTS at Chelsea, he and Graham Rix would take me out on to the training pitch after everyone else had gone and make me work on my left foot.

'They said, "You've got Desailly, Leboeuf and Duberry, all right-sided. Now get over here and use your left foot". Ray would get it on his left foot and 'ping', get it on his right foot and 'ping'. I was a 17-year-old going 'wow'.

'He spent two years with me doing that, teaching where and how to strike it. So when I first came into the team I was straight in because nobody wanted to play on the left. Ray's a big part of where I am today.

'I've shown I'm not scared of taking a step back. It's why I went to play in the Championship because I didn't want anyone to think that I didn't know about life outside the Premier League. Well, I do now.

'I see what Frank Lampard has done at Derby and what Stevie G is doing at Rangers and I want a piece of that, too. They've gone into big jobs. I've always had a fascination with management and coaching.

'When Gianfranco Zola first came to Chelsea, he would take a bag of balls in the afternoon and stay out for hours, taking the kids with him. I'd go one-on-one against him and he'd beat me 10 times, then he'd spend 20 minutes talking to me about what I should do to try to stop him. "Adjust your feet a little bit more, do some quick feet-work before training, activate your muscles, be ready".

'Then he'd come and sit in the changing room with us kids, ask us questions. And do you know something? He'd know the names of everyone. He made such an impact on me. The next day, he'd been in two hours before the start of training, stretching and massages, eating the right breakfast. He asked for an Italian chef and for us to do the right things. He showed us what we had to do.'

Clearly, as well as Zola, Mourinho's arrival in English football impacted on Terry. We return to the subject of his coaching books.

'After the first session — it only lasted an hour — the lads were in the dressing room and we couldn't believe what had just happened. Unbelievable. He was clearly something else. It was the intensity of the session, the planning that had gone into it.

'So I went to the analysis guys and asked for a notepad so I could write down what he was doing. From his first pre-season, I've got every session mapped out. What we did, how long we did it for, comments from the players. It went from there and I kept doing it.

'He'd be in early, putting out the cones and preparing. It could be raining hard, but he'd still be out there. In a training game, he'd demand full match intensity.'

Does he see the same from Mourinho now? 'At every club he has had big characters and I'm not sure he has that at Manchester United at the moment. At Chelsea, he did.

'He embarrassed me after one pre-season, after we had won a league title. He stopped the training session, came in, threw down his pad. "If you keep giving the ball away, I will go and buy someone for £50million".

'I am thinking, "I played every game for you last season! And now you're trying to humiliate me!" I didn't understand why he was doing that, but my instinct was to run and give everything; flying into tackles, winning the ball.

'We made eye contact and he grinned. He knew exactly what he was doing — to get the best out of all of us. I have seen him do the same to Frank Lampard, Didier Drogba, Ashley Cole, Michael Ballack. Big personalities in the dressing room.

'Does he have the same now at United? You have to stand up and turn up at training every day and show him that you want to win at all costs. If you've got that, he's 100 per cent on your side.

'I do think he'll bring success to United, but it needs patience. My top three for this season will be decided between City, Liverpool and Chelsea. That leaves United and Spurs fighting for fourth.'

Such experiences and analysis would see this warrior of the penalty box sit nicely in a television line-up soon, if not now.

He agrees. 'I look at what Gary Neville, Jamie Carragher, Jamie Redknapp — and Graeme Souness, I love Graeme — are doing with Sky and how the BT lads are doing it. It's changed. It used to be that you might turn up just before the programme airs, now they are there all day preparing. You can see that via their social media and I have seen it first hand when I did Monday Night Football.

'Modern dressing rooms respect it because they know these guys have done it at the highest level and they are working at it. If I do it, I want to be as good as them.

'When I look back, I don't see myself as the most talented player ever but I am a winner. I see someone who went in and gave 100 per cent every day, with Chelsea and Villa. So whether that's Sky, BT, beIN Sports, ESPN.

'If that's another dressing room as a player or a coach, that's what you get. I would want my team and players to represent who I am. If you have this, I believe, along with the talent and knowledge in football, it becomes a great recipe. That's what I am about.'

During his time at Villa Park, John Terry believes he came across a real star in Jack Grealish.

'Jack will be a big, big player,' he says. 'I hope Villa can come up and he gets his chance in the Premier League that way. I can see why Spurs wanted him.

'Right now he's in the right place. I think he will become a top Premier League star and an England international.

'He reminds me of Gazza, with his balance and his skill, the way he receives the ball and drives at defenders.

'He is looking after himself off the pitch as well. He's a great lad.

'He eats the right way and got the chef on board at the training ground. He was cooking for Jack there as well as sending him home with the right food.

'That will serve him well. He's an ambitious boy who will go right to the top if he continues doing the right thing.'