Chelsea left-back Marcos Alonso admits he will have to work very hard at Stamford Bridge to become one of the best left-backs in the game.
The 25-year-old was a deadline day signing for manager Antonio Conte together with David Luiz.
It will be his third spell in the English Premier League after featuring for Bolton Wanderers and Sunderland.
"Chelsea is a step up, there is no doubt about it," he told Chelsea's official website.
"It's the next chapter in my career but I need to keep working hard and doing well if I want to be one of the best left-backs in the world.
"I've learnt a lot in Italy about tactics, it's something they work on a lot and I'm sure Antonio is the same. I'm ready and it's good for me if I can play in more than one position because it's helpful for the team.
"The [Chelsea] squad is amazing and we only have top players here, so I think we will fight for every competition.
"I knew of Chelsea's interest a couple of weeks ago so I've watched the first few games and the team is winning, and winning well."