Manchester United defender Timothy Fosu-Mensah is set to join Crystal Palace on a season-long loan, Press Association Sport understands. The 19-year-old Dutch defender, signed from Ajax in 2014, made his first-team breakthrough under Louis van Gaal and last season played 11 times under Jose Mourinho.However, Fosu-Mensah made just four starts during the 2016/17 season and now looks set to complete a loan move to Frank de Boer's Palace.Compatriot Jairo Riedewald, another former Ajax player, has already arrived at Selhurst Park this summer to bolster a defence that no longer has Mamadou Sakho to call upon.Fosu-Mensah, who has a deal at Old Trafford until at least 2020, is set to get valuable first-team football at Palace, although the teenager insists he was not frustrated by a lack of opportunities last term."It's fine because you're surrounded by great players," he recently told Press Association Sport."Every day, in and out, you train with great players. You develop every day with these great players."I just want to develop, keep developing. I am young so I try to work on my weaker stuff and to become a better and complete player."I need a bit of experience, things like concentration, touches, communicating on the pitch."Fellow United defender Cameron Borthwick-Jackson has joined Sky Bet Championship side Leeds on loan for the 2017-18 season.