Gelson Dany Batalha Martins (; born 11 May 1995) is a Portuguese professional footballer who plays as a winger for Ligue 1 club Monaco. He began his career at Sporting CP, appearing in 125 competitive matches and winning two trophies during his three-year tenure. In 2018, he signed with Atlético Madrid and, the following year, joined Monaco, initially on loan. A Portuguese international since 2016, Martins represented the nation at the 2018 World Cup and the 2017 Confederations Cup. Club career Sporting CP Born in Praia, Cape Verde, Martins moved to Portugal in his teens and played youth football with C.F. Benfica and Sporting CP. In March 2014, he was promoted to the B team of the latter and signed a contract lasting until 2019 and which included a release clause of €45 million. During his youth spell, his goal against C.F. União de Coimbra earned the praise of many, even though his coach at Sporting B had previously said that he was being "harmed" by not playing in his preferred position as winger. Martins made his professional debut on 24 August 2014, coming on as a late substitute for Lewis Enoh in a 1–0 away win against S.C. Olhanense in the Segunda Liga. On 21 December, he scored his first goal in the competition, contributing to a 3–1 victory at Vitória S.C. B. In summer 2015, Martins was promoted to the main squad by new manager Jorge Jesus. He made his competitive debut on 9 August, playing injury time in a 1–0 win over S.L. Benfica in the Supertaça Cândido de Oliveira. Martins first appeared in the Primeira Liga on 14 August 2015, playing one minute in a 2–1 defeat of newly promoted C.D. Tondela. On 15 January of the following year, against the same opponent, he scored Sporting's 5,000th goal in the competition, putting the hosts ahead in an eventual 2–2 draw. On 11 June 2018, Martins requested that his contract with Sporting be terminated following an incident in May in which a group of around 50 supporters invaded the club's training centre and assaulted several players and staff members. Atlético Madrid On 18 July 2018, Martins accepted an offer from Atlético Madrid. One week later, he was announced as a new player of the Spanish club after agreeing to a five-year deal on a free transfer. Sporting made an official complaint to FIFA over the transfer and