Everton have moved ahead of at least three other Premier League clubs after bidding £18m for Real Madrid left-back Sergio Reguilon.
The offer is expected to spark a flurry of activity for the 23-year old Real academy product, who was voted the best left-back in La Liga last season.
Reguilon played a pivotal role during a season-long loan at Sevilla, becoming a fan favourite as he helped them finish fourth and secure Champions League qualification.
Everton boss Carlo Ancelotti is keen to fill the vacancy left by Leighton Baines - who retired on Sunday - and provide competition for Lucas Digne.
Real rate their young star highly, but are blessed with talent in the left-back position and drastically need to raise funds, a reported €200m (£180m), to help balance the books.
As well as the experienced Marcelo, now 32, Real Madrid have Frenchman Ferland Mendy, who has enjoyed an impressive season at the Bernabeu.
Sevilla remain keen to take Reguilon on loan for another season, but are aware his performances have brought him to the attention of major teams across Europe.
The summer transfer window will run for 10 weeks from July 27 and close at 11pm on October 5.
A domestic-only window for trades between the Premier League and EFL then runs from October 5 and closes on Friday October 16 at 5pm. Follow all the news and analysis on Sky Sports News and across Sky Sports' digital platforms, including with our dedicated Transfer Centre blog.