West Ham raked in a tidy fee from Pablo Fornals' sale to Real Betis.
The Spain midfielder returned home on Friday after Betis were cleared to sign him with the winter market shut.
Mundo Deportivo says Betis have paid 7m to sign Fornals.
The attacker also joins Betis on a contract to 2029.
Fornals will be available for selection with Betis from next week.