United booked their place in the last eight of the competition on Wednesday night after a hard-fought 3-0 win over the Seagulls at the Amex Stadium.
Despite the eventual scoreline it was a tricky tie to overcome for United with Scott McTominay netting a vital opening goal from a Juan Mata free-kick just before half-time.
After the break Brighton started the brightest and they almost levelled the scores when substitute Leandro Trossard was denied from close range by goalkeeper Dean Henderson.
The save proved to be vital in the end as United went on to score twice more through Mata and Paul Pogba to secure their place in the quarter-finals.
Spanish midfielder Mata was given the official man of the match award for his excellent display, but summer signing Van de Beek remembered to praise Henderson for his role in the win.
“Really, really nice save from him,” Van de Beek told MUTV. “Also important moment otherwise it is one-one. Amazing save from him and I think also a really important moment in the match.”