Manuel Lanzini is leaving West Ham United to return to River Plate.
Lanzini agreed with West Ham to leave this summer after helping the Irons to their Europa Conference League final victory over Fiorentina.
The Argentine, 30, has now agreed terms with River - nine years after leaving for the UAE's Al-Jazira.
River president Jorge Brito announced: "We closed an agreement a few hours ago with Manu Lanzini. He is already a River player.
"Manuel is a free player today and will sign for a year. He is a unique player for his characteristics, for the league he comes from and I think it's very important for us to sign him at this time of the season."