Former Manchester United defender Axel Tuanzebe is suing the club for alleged negligent medical advice.
The 27-year-old, who joined Burnley earlier this month, filed a legal claim with the High Court against United last week.
It relates to a period from July 2022 involving an unknown injury and is considered a high value claim, which is understood to be more than £1m.
Tuanzebe was out for 195 days in his final season at the club before he was loaned to Stoke in January 2023, where he made just five appearances.
He joined the club when he was eight, making his debut in 2017, and played 37 times for them before leaving in the summer of 2023, joining Ipswich as a free agent that September.
The right-back captained United at every level and his final appearance for the club was in the 2021 Europa League final loss to Villarreal, where he scored in the shootout as they lost 11-10 on penalties.
The former England Under-21 international – who now represents DR Congo – also had three spells on loan at Aston Villa, while he also spent time at Napoli in 2022.
Tuanzebe’s lawyers, Simons Muirhead Burton, and United both declined to comment when approached by BBC Sport.