Manchester United are locked in talks with the agent of Sporting CP midfielder Bruno Fernandes.
The representative of Sporting's star midfielder, Miguel Pinho, has been in England in recent days, says ESPN.
There have been informal meetings with Pinho in London.
Discussions within those meetings covered a range of topics as the possibility of him joining United is probed.
It is said Fernandes would likely cost around £65m, which would make him United's third-most expensive ever signing.
United have only spent more on Paul Pogba and Romelu Lukaku in their history.