Manchester United have had a £40m bid for Aaron Wan-Bissaka rejected by Crystal Palace, according to Sky sources.
United need a long-term replacement for Antonio Valencia and have targeted the England U21 defender.
Wan-Bissaka has three years remaining on his contract and Crystal Palace are holding out for at least £60m for his services.
The 21-year-old made his Palace debut in February 2018 and became a first-team regular this season, making 39 appearances as the team finished 12th in the Premier League.
Other potential right-back targets for United are Paris Saint-Germain's Thomas Meunier and Tottenham's Kieran Trippier.
United have been already been busy ahead of the opening of the transfer window on June 11, with a deal agreed in principle for Swansea winger Daniel James.
Juan Mata has been offered a new contract but Ander Herrera and club captain Valencia were released.
United begin their pre-season against Perth Glory on July 13 and will remain in the city for a friendly game against Leeds United four days later.
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