Why Man Utd scouring centre-back market may be bad news for Martinez

Manchester United's impending busy summer of business has been widely documented. The club are expected to back their new permanent head coach - Michael Carrick or not - with at least two midfielders, a left-winger and a left-back. Matthijs de Ligt, Harry Maguire (new contract pending), Leny Yoro, Lisandro Martinez and Ayden Heaven make up a sufficient centre-back department for the return of two games a week next season.