Arsenal youngster Krystian Bielik says he is adjusting to English football after being converted to a centre-back for the club's under-21 side.
Bielik, 17, joined the Gunners from Legia Warsaw as a defensive midfielder earlier this year, but has been playing at the heart of defence for Steve Gatting's reserve side this season.
Arsene Wenger's senior side have had injury worries at centre-back this season, and Poland under-17 international Bielik says the role is helping him cope with the physical demands of the English game.
"The physicality was something new for me," he told the club's official website. "I only started playing centre-back this season and it's the first time I've had to mark strikers who are running in behind.
"It's also the first time that I've had to win headers. When I play in defensive midfield I don't really have to run as much to mark players, so marking a striker at centre-back is a lot more physical and has been a new experience for me.
"A lot of the time they ran behind me to go one-on-one with our goalkeeper, so that is definitely something that I need to improve on.
"We spoke a lot after the game and the coaches told me what I needed to do to improve and this has really helped me, and I think I really improved on that in the West Ham United game.
"It also really helps to have Julio Pleguzuelo playing alongside me because he controls our defensive line and tells me when to get up. He is a great leader and really helps me play well because of all the advice he gives me."
The Gunners were the only side in the top five European leagues not to sign an outfield player this summer.