West Ham United have entered advanced talks with Sporting Lisbon over the signing of defensive midfielder William Carvalho, according to a report.

The 25-year-old, rumoured to have been on the radar of a number of Premier League clubs over the past two years, is said to have a £40m release clause in his contract.

Sporting are determined to hold out for that full sum to be paid, and Sky Sports News reports that West Ham may now be willing to cough up as they fear another side joining the race.

United are understood to have had an opening offer, well below the £40m mark, rejected by the Portuguese outfit earlier this summer.

Carvalho was left out of Sporting's squad to face Steaua Bucuresti in a key Champions League qualifier earlier this week, with Rodrigo Battaglia recently brought in as a replacement.