Wojciech Szczesny has claimed that Arsenal teammate Calum Chambers has proved himself a "massive signing".
The 19-year-old has impressed in the early stages of his Gunners career following a £16m summer switch from Southampton.
Consequently, the Polish goalkeeper admits that he is surprised at how fast the England international has adapted to the demands of being at a "big club".
"It is a strange one because I would imagine that to be very successful at 19 you need to be massively confident, maybe over-confident at times. But Calum isn't - he's very humble, very quiet and he shows his confidence on the pitch," he told Arsenal's official website.
"It is a massive quality because he looks very comfortable, whether you play him at right-back or centre-back. He is comfortable on the ball, he is comfortable defending and he is very strong as well. He has been a massive signing.
"The pressure was on him as well because he was 19, he came to a big club and he went straight into the starting XI but he has been coping very well."
Chambers has made 10 appearances in all competitions for Arsenal this season, along with two for England.