Jack Butland has described his growing rivalry with England goalkeeper Joe Hart as "tough".
The Manchester City stopper has been the first-choice keeper for England since 2010, but has found increasing competition from Butland since he took over the No.1 shirt for Stoke City.
The former England Under-21 captain told The Telegraph: "It works, but it's tough. I know that Joe's the established number one but when I go away [with England] I know it's another opportunity to test myself, to battle against him, to try and make more saves, to try and perform better than him each time we train.
"I've known Joe a long time. I've got a lot of respect for him and he's been like a mentor for me, a role model. I look up to him. Training is respectful, it's good fun, it's light-hearted but the minute you are there dealing with a shot, it's all-out battle.
"When I am number two and I am working as hard as I can then quite often the keeper ahead starts to raise his game even more. It can be a Catch-22. I've been in both scenarios, so I am just doing what I can."
Butland kept a clean sheet as Stoke beat Hart's Man City 2-0 last weekend.