Arsenal have confirmed the signing of the teenage midfielder Krystian Bielik from Legia Warsaw for a fee understood to be close to £3.25m.

The Poland youth international, who also had talks with Hamburg, will be included in the first-team squad, despite only having made six appearances for Legia.

Speaking before the deal was formally announced, Arsène Wenger said: “He’s a defensive midfielder, 6ft 2in, he has a good energy level and technical level.

“It’s a gamble but, on what we saw, it’s worth to take the gamble. It’s an awful lot of money for a player if he doesn’t succeed. If he does succeed, then it’s cheap.”