Forward Kamaldeen Sulemana has left Southampton to join Italian side Atalanta for a fee that could rise to £18m.
Sources have told BBC Radio Solent that the Saints have a sell-on clause in the agreement.
The 23-year-old was signed by the Saints back in 2023 for a club-record fee of £22m and made 74 appearances.
Sulemana links back up with previous Southampton boss Ivan Juric at the Serie A side.
The Ghana international moved to St Mary's from French side Rennes on deadline day in February 2023 and scored four goals and registered seven assists in his two-and-a-half years on the south coast.