Jones suffered from mild thrombosis at the start of the campaign but he had been playing in recent weeks.
It is unclear if he is injured or being rested but he would have been disappointed to miss the game at Selhurst Park.
Chris Smalling has flourished this season with a consistent run of games and the hope for United supporters was that Jones could do the same.
Phil Jones misses out today due to being in the ‘red zone’ in terms of his fitness, says Louis van Gaal. #mufc
— Manchester United (@ManUtd) October 31, 2015
Injuries and time out are really are beginning to hold Jones back in terms of his United career.
Van Gaal wanted a centre-back this summer and it is clear to see why as Jones cannot be relied upon. His absence means Daley Blind, midfielder by trade, lined up at the heart of defence against Palace.