Martial is reported to have reached a contract stalemate with Old Trafford officials amid concerns over his playing time under Jose Mourinho. His present deal expires in the summer of 2019 – but United retain the option of a one-year extension.
Since Alexis Sanchez joined the club in January, Martial has not scored and has started only four games – including defeats at Tottenham and Newcastle and he was then substituted on 64 minutes against Chelsea.
Martial is also said to be unhappy that he was asked to operate on the right wing rather than his preferred left side to accommodate Sanchez.
Barcelona considered a bid for Martial last summer before they moved for Ousmane Dembele but the Catalans may now return for the French forward in the coming window.
Barcelona are also confident they lead the race to sign French forward Antoine Griezmann from Atletico Madrid this summer, while their scouts are also monitoring the rapid progress of Fulham’s Ryan Sessegnon.
The 17-year-old has scored 14 goals in 43 games for Fulham this season and was named on the six-man shortlist for the PFA Young Player of the Year award alongside Harry Kane, Marcus Rashford, Leroy Sane, Raheem Sterling and Ederson.
