Manchester United is considering whether to sign a new goalkeeper to replace Onana, 29, after a series of mistakes in recent games.
Vanja Milinkovic-Savic, 28, has had a successful season at Torino, and several clubs, including Manchester United, had been linked to him. However, it appears that Napoli will be signing him instead.
Transfer expert reports suggest that the Serbian goalkeeper is close to joining Napoli, while Cyril Ngonge may join Manchester United on loan. Leeds United was also interested in Milinkovic-Savic as they deal with their own goalkeeping issues.