Joao Mario has agreed a new five-year contract at Sporting Lisbon, which includes a minimum release clause of €60 million.
The Portugal international broke into the first time under Marco Silva last term, having spent the previous season on loan at Vitoria Setubal, and impressed in the Supertaca Candido de Oliveira victory over Benfica on Sunday.
The 22-year-old looks set to play a key role during Jorge Jesus' debut Sporting campaign, especially with William Carvalho's fractured tibia set to rule him out of the Primeira Liga's early stages.
Mario had reportedly been the subject of interest from La Liga side Atletico Madrid, although a new deal means he is primed to continue his development at Sporting.
Jesus' men begin their domestic campaign against Tondela on Friday.
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