Southampton defender Lyanco has joined Qatar Stars League club Al Gharafa on a season-long loan deal.
He has only featured once this season, starting the EFL Cup first-round defeat by Gillingham on 8 August.
Meanwhile, midfielder Kazeem Olaigbe has left the club in a permanent move to join Belgian side Cercle Bruges.
The 20-year-old Belgium youth international leaves St Mary's having never made a first-team appearance.
He joined Saints from Anderlecht as a 16-year-old and played six times for Saints Under-21s, scoring six goals.
Olaigbe was sent on loan to Ross County at the start of last season before joining Harrogate Town, also on loan, in January.