Newcastle has lodged a £13m bid with Sporting CP for defender Ruben Semedo.
According to Portuguese publication O Jogo, the Magpies are determined to make the 23-year old their second signing of the summer, after securing Chelsea winger Christian Atsu last week.
The report suggests Newcastle's offer is below the £17m evaluation given by Sporting, who have also fielded an offer from French Ligue One side Lille.
However, Semedo is leaning towards a move to England rather than France.
Everton, West Bromwich Albion, Crystal Palace, Southampton and West Ham are also reported to be interested in the centre-back.