Brentford have made an offer for Braga left-back Francisco Moura.
The Sun says the Bees had made contact regarding a potential deal for the 22-year-old – who has a £25million release clause.
And it is now understood the Premier League side have made an offer for Moura slightly below that clause in an attempt to get it over the line in this winter window.
Braga and their president Antonio Salvador are notoriously resolute when negotiating deals for players.
Last January, the Primeira Liga club refused a £3.3m loan offer from Liverpool for central defender David Carmo to replace the injured Virgil Van Dijk – which included a further £16.6m option to buy.
Carmo also had a £25m release clause in his contract.
But Salvador has previously admitted Braga need to sell at least one star name a year to balance the books.