Manchester United have triggered the one-year option in Timothy Fosu-Mensah's contract.
Fosu-Mensah, 22, was approaching the final months of his deal but the MEN understands United have extended his contract to 2021.
The extension follows United's decision to activate the two-year option on Eric Bailly and one-year extension in Nemanja Matic's contract, although United are in negotiations about a new deal for the Serbian. Angel Gomes, 19, is the only first-team squad member out of contract at the end of the season and United do not have a one-year option on his deal.
Holland international Fosu-Mensah has not played for United since the final day of the 2016-17 season against Crystal Palace, having spent the last two seasons on loan at Crystal Palace and Fulham. Fosu-Mensah sustained anterior cruciate ligament damage playing for Fulham last April and has not played a competitive match since.
Fosu-Mensah started eight United games and made 13 substitute appearances under Louis van Gaal and Jose Mourinho, but is yet to figure under Ole Gunnar Solskjaer. Fosu-Mensah has appeared for the Under-23s twice this term.
United signed Fosu-Mensah from Ajax in 2014 and Van Gaal gave the Dutchman his debut against Arsenal in February 2016. Fosu-Mensah lined up in the FA Cup quarter and semi-final wins over West Ham United and Everton later that season.
Despite his lack of playing time in 2016-17, Fosu-Mensah was named on the bench by Mourinho in the Europa League final victory against Ajax and received a winner's medal.
Fosu-Mensah rejected the option to join Huddersfield Town on loan midway through last season after being frozen out by Fulham manager Claudio Ranieri. The Italian eventually recalled Fosu-Mensah, who played more regularly under Ranieri's replacement Scott Parker, before he was injured.
