Gelson Martins
Gelson Martins has reportedly been watched by Manchester United Getty Images

Manchester United are reportedly monitoring the progress of youngster Gelson Martins. The 21-year-old Sporting Lisbon winger is also said to be attracting interest from Spanish giants Real Madrid and is widely considered to be one of the most exciting prospects in Portuguese football.

Martins caught the attention of clubs across the continent after he produced an eye-catching display in Sporting's 2-1 defeat to Madrid earlier this week, according to the Portuguese Daily Record. However, Sporting are keen to extend the youngster's deal at Estadio Jose Alvalade in an effort to ensure he remains with the club in the short term.

Sporting manager Jorge Jesus recently admitted that the reported United transfer target is a unique player in his home country. "In Portugal there is no one like him," Jesus said, according to ESPN.

United previously signed Cristiano Ronaldo and Nani from Sporting in 2003 and 2007 respectively. Both players enjoyed trophy-laden spells at United before they moved on to other clubs. Meanwhile, United's former assistant coach, Carlos Queiroz, managed the Portuguese club between 1994 and 1996.