The 20-year-old will spend the 2018/19 campaign with the newly-promoted Cottagers, who beat Aston Villa 1-0 in the Championship play-off final at Wembley last season.
The move comes on the back of the versatile youngster impressing during pre-season for the Reds, as he appeared in all five of United’s Tour 2018 games in the United States and was a second-half substitute against Bayern Munich last weekend.
It will represent a second successive season out on loan for the Netherlands international, who made 24 appearances in all competitions and caught the eye during his spell at fellow Premier League side Crystal Palace last term.