With Middlesbrough looking almost certain to be relegated, its likely the 26-year-old will leave in the summer.
According to the Watford Observer, 'the Hornets are likely to have to battle for the Dutchman’s signature, however, with both Southampton and Bournemouth interested.'
De Roon joined Boro from Italian side Atalanta last summer for £12m and has made 28 Premier League appearances, scoring three times for the club.