José Mourinho has insisted he is returning to Chelsea a better and more mature manager than when he left in 2007, claiming he wants to stay at the club “for a long time” after agreeing a four-year contract. Mourinho, who will be officially introduced next Monday, completed the formalities of his protracted move in London on Monday and insisted he was ready to “marry again” after agreeing a return to the club he professes to “love” following a five-minute conversation with the owner, Roman Abramovich. Mourinho is set to become the highest paid manager in the Premier League with a reported £8.5m salary, and brings with him two members of his backroom staff, the fitness coach Rui Faria and goalkeeping coach Silvino Louro, who worked at Stamford Bridge during his previous three-year spell, when Chelsea won two league titles, one FA Cup and two League Cups. The technical assistant, José Morais, also follows from Spain while Steve Holland, Christophe Lollichon and Chris Jones will remain from the existing coaching setup. Mourinho, 50, left Chelsea six years ago after his relationship with Abramovich had seriously deteriorated, but claims he has matured following successful spells at Internazionale and Real Madrid, saying his…