Fabio Vieira will join Arsenal from Porto for a reported £34 million, plus add-ons.

After Brazilian attacker Marquinhos and goalkeeper Matt Turner, the 22-year-old is the third summer addition for the Gunners. The upfront payment from Arsenal is £30 million, plus £4 million in performance-based add-ons.

Last season, Vieira made 15 starts for Porto and scored six goals in the league. He has also scored 13 goals in 21 appearances for Portugal’s Under-21 team.

Mikel Arteta, the head of Arsenal, said: “I’m overjoyed that we were able to find and sign such a unique talent.

“Fabio is a very imaginative player who will enhance our offensive performance with his high caliber and adaptability.