Michael Laudrup believes that bringing success to Manchester City will be the "biggest challenge" of Pep Guardiola's managerial career so far.
Laudrup, who was a teammate of Guardiola's at Barcelona and spent 20 months in charge of Swansea City, warned that the Premier League will be unlike anything he faced during his time at the Camp Nou and Bayern Munich.
"The Premier League is very difficult," Laudrup said in a Sky Sports documentary. "One week he's playing against Arsenal in one way, the week after he's playing a team that's more direct, whereas in Spain they all try to play the same way and in Germany as well. So this will be his biggest challenge."
Laudrup said that Guardiola showed he had an extraordinary understanding of the game from the moment he made his playing debut for Barca as a 19-year-old in 1990.
"I remember his first game, we had a couple of injuries in that position -- defensive midfield -- so suddenly this young, skinny guy came up from the youth team," Laudrup added. "We're at home, 85,000 people in the stands, but he did his work and he did it great.
"You could see immediately that he was very intelligent. Because of the position he was in, it was very important to talk a lot, to help the players in front of him. You're very used to this in the UK but in other countries it's not so common. But Pep did that from a very early stage, he definitely had a great vision and he knew what he had to do and how he wanted to play."
Xavi, Guardiola's former captain at Barcelona, believes the Catalan is capable of transforming the English game.
"I think that Pep, due to his standing in modern football, could change things," he said. "I think that he is one of the few people who can change English football.
"The first thing I remember him saying as coach was that he wouldn't tolerate any player not working hard. What Pep really hates is losing the ball.
"In Barca's philosophy, losing possession is irresponsible. It's just not good football. If you lost the ball in the middle of the pitch, you knew Pep would be there, fuming on the touchline.
"The high pressing was brilliant. It was a real football revolution. We made history. Not just for the victories, but also for the way we played. He didn't just change Barca, he changed world football."
Former France striker Thierry Henry, who also worked under Guardiola at the Camp Nou, expects his former boss to be a success in England.
"He wants to control everything. Arriving late? Impossible. If you don't train with the right intensity, that's also impossible," he said. "You had to be at home before midnight and everything was so detailed. Everything that you can imagine he had control of it, it was just crazy.
"His philosophy will work, because that's how he his."