Atletico Madrid have completed the signing of 23-year-old winger Gelson Martins from Sporting Lisbon.

The midfielder has joined the Spanish outfit on a free transfer after his contract with the Portuguese giants expired.

Martins cancelled his contract at Sporting earlier this summer, citing cause following an attack by fans at the club’s training base.

The Portugal international has now joined Atleti on a five-year deal, keeping him at the Wanda Metropolitano until 2023.

“I feel the club is constantly growing in a strong manner and that’s necessary for the growth of the team,” Madrid manager Diego Simeone told reporters.

“Gelson is a lad who’s constantly improving. We saw it last year and his characteristics can help us, He’ll give us competitiveness on the right wing and offensively if we play with three up front.”

Martins has scored 25 goals in 125 appearances for Sporting over the past three years.