Bacary Sagna has declared that Eliaquim Mangala will become one of the world's best defenders and said Manchester City's biggest summer signing is like family to him.
Right-back Sagna and centre-back Mangala are France teammates who both joined the Premier League champions this summer and the former Arsenal player is helping his younger colleague adjust to life in England.
He is convinced that Mangala, who became the most expensive defender in the history of English football when City paid 32 million pounds for him, has the ability to reach the very top.
He said: "He has everything he needs to be a top player and I'm sure he will be. To me he will be one of the best defenders in the world, but he's still young and there's a lot of room to improve. He will keep working hard and I'll be pushing him to become of the best.
"I'm everything to him. He's like my twin brother, my son. I see him more than I see my family, so our relationship is really important.
"It's my responsibility to help him. I remember when I came here I didn't speak proper English. But he's a lovely guy and he's settled in well."
Sagna has only started one league game for City as he competes for the right-back spot with Pablo Zabaleta, but said the rivals are friends and he relishes the task of trying to displace the Argentine from the team.
He added: "I knew before coming I would not play every single game but I came for that reason -- I need to challenge myself. I need to work even harder to try to become better. Zabaleta is one of the best in the world. But everything is fine, we have a good relationship.
"He was one of the first players to speak to me at the training ground. When you first come in, you are a bit in awe, a bit shy.
"We have to keep a good mentality in the team. It's vital. We want to be competitive and we have games every three days. We all need to be ready whatever happens and be ready to play."
Sagna is hoping to return to the City side when they host Tottenham on Saturday and the defender, a veteran of North London derbies, believes Spurs could be title contenders.
"Yes, I think so," he said. "They've always been near the top. They have always been a tough opponent. They have quality players and a good team. They can finish near the top. We must focus on our team though and not worry about others.
"There are a few teams in with a chance. So many teams are capable of beating anyone on their day -- that's why it's the hardest league in the world. It's definitely the most competitive league in the world. Even when I go to France, every player I speak to speaks about the Premier League."
Sagna broke his leg playing against Tottenham in 2011 but said: "It was in the past. Generally it was always a pleasure to play against them, but that was one of the hardest moments in my football life -- but I came back stronger."
His former Arsenal teammate Emmanuel Adebayor moved on to City before going to Tottenham.
Sagna said: "He's a funny guy, a very lovely guy. He gives his best for his club. He used to play for Arsenal and when I played against him it was quite challenging. Now he plays for Tottenham and he's coming up against another of his old clubs so he'll be extra motivated, but he's not the only one we must worry about."