Portuguese winger Gelson Martins will join Atletico Madrid from Lisbon-based Sporting on a five-year deal as a free agent, the Spanish club announced yesterday.

The 23-year-old Portuguese international was one of nine players to quit Sporting after they were attacked by hooded fans, some armed with sticks, during a training session following their failure to qualify for next season's Champions League. "His speed and fine dribbling skills make him a valued addition to our team and a threat to the opposition's defenders," the club said in a statement. Martins played 140 matches for Sporting Lisbon and scored 27 goals with 30 assists. He made his debut for Sporting in 2015 when he was just 19 years old. He has been capped 19 times for Portugal and was part of their squad for the 2018 World Cup in Russia, appearing as a substitute in the 1-0 win over Morocco.