Arsenal and Manchester City have reportedly entered the race to sign Idrissa Gueye from Premier League rivals Everton.
The 29-year-old is rumoured to have asked for a move away from Goodison Park this month following interest from Paris Saint-Germain.
PSG tabled a £21.5m offer for the Senegal international last weekend, which Everton - who value the player at nearly double that amount - were quick to knock back.
Marco Silva left Gueye out of his squad to face Huddersfield Town on Tuesday night, but he put that down to a minor groin injury and nothing to do with the interest from elsewhere.
Sky Sports News suggests that Silva's hopes of keeping the former Aston Villa star in place may have suffered a blow, however, as Arsenal and Man City could be about to make a move.
PSG signed Leandro Paredes from Zenit St Petersburg on Tuesday, though they are still believed to be in the running for Gueye.