Arsenal defender Calum Chambers has joined Middlesbrough on a season-long loan deal.

The 21-year-old was expected to leave the Emirates Stadium on a temporary basis in order to gain first-team experience in the Premier League following the signing of Rob Holding and imminent arrival of Shkodran Mustafi.

West Bromwich Albion had been credited with an interest in the England international, but Middlesbrough have now won the race for his signature.

"I'm really pleased. It's a position where we've been working towards bringing the right player in. We haven't been in a hurry because Calum was the player we were waiting for, and he's going to help us a lot," Aitor Karanka told the club's official website.

"I'd like to say thank you to him because we know he had another offer, but he wanted to come here. That's important and we're looking forward to working with him."

Chambers could make his Boro debut against Crystal Palace after the international break.