New Chelsea goalkeeper Asmir Begovic has insisted that he joined the club to challenge himself, and intends to push Thibaut Courtois hard for the number one jersey.

The Bosnian international moved to the Blues from Stoke City for £8m, but revealed that manager Jose Mourinho has not given him any guarantees over first-team action.

He is quoted as saying by The Telegraph: "I want to test myself against Thibaut, he's one of the best goalkeepers in the world but I believe in myself. I want to try and get as many games as I can. There have been no guarantees from the manager. The challenge that's here, the manager and ­players was what attracted to me. I'll back myself, absolutely.

"I'll be ­keeping my head down and ­working hard to see how I can help this team in the future. Obviously everyone has their opinion but for me it was more of a challenge to try something different.

"I think I was at that stage where I want to test ­myself against the best and that's ultimately what I've come here to do. Hopefully every time I can show everybody what I'm all about and ultimately help this team."

Begovic could make his Chelsea debut against Arsenal in the Community Shield on Sunday.