Former Barcelona captain Carles Puyol believes Pep Guardiola has taken on his greatest challenge in the Manchester City job.
Puyol enjoyed four successful seasons under Guardiola at Camp Nou, winning three LaLiga titles and the Champions League in 2009 and 2011.
Guardiola then went on to enjoy further success with Bayern Munich, lifting the Bundesliga trophy in each of his three seasons, although glory on the European stage eluded him.
Now at City, Guardiola has made a strong start to his tenure, winning his first 10 matches in all competitions before a slight wobble last week saw them follow a 3-3 draw in the Champions League at Celtic with a 2-0 loss at title rivals Tottenham on Sunday.
After dominating in Spain and Germany, Puyol says Guardiola has his work cut out to repeat the feat in the Premier League but backed his former coach to oversee a cultural change in English football.
"It's the biggest challenge for Guardiola but I think he will change football in England," he said.
"A lot of people say football is different in England to other countries but the way Guardiola works and puts pressure on his players will change football here a bit.
"His biggest challenge is to change the direct style of football. Now in England the football is more direct, with big centre-backs. I couldn't play there because I'm too small.
"Guardiola wants to start playing from the back with intelligent play from the goalkeeper. It doesn't mean he won't play long like against Manchester United when they scored a goal with three touches, but it's the whole style. He is based on ball possession and playing from the back.
"I have seen his influence on the team very quickly. He is doing very well, he has very clear ideas which he tries to transmit to the players. He is the best coach I ever worked with and I'm pleased to see him in England.
"There are a lot of coaches worse than him. He puts a lot of pressure on the players but the players feel free under Guardiola. It's tough but I understand football like that, I enjoy it.
"Guardiola thinks everyone can improve and play at a higher level - and every player improves with him. It also motivates the players to improve."