de Ligt wouldnt be classed as U21 for CL purposes until he’s been at the club for 2 years. He would therefore take up a CL place if signed - unless the rules have changed!We're also likely to add at least 4 non HG slots to the CL roster with the exits of Sissoko, Llorente, Alderweireld and Dembele. Not to mention de Ligt wouldn't count against that requirement should we eventually bring him in this summer.