Joao Mario will return to Portugal and join Sporting Lisbon on a loan spell. The midfielder spent last season on loan at Lokomotiv Moscow.
The Russian side did not exercise their option to buy the player from Inter.
Inter could not secure a permanent move for the player. Some English clubs were keen on bringing the former No.10 but no concrete offers were presented.
Joao Mario joined Inter for a staggering 44 Million deal from Lisbon in 2016.