Magpies manager Alan Pardew confirmed the attacking midfielder was among the group that wouldn't play on Sunday:
Craig Hope of the Daily Mail provided further details about the ailment:
As revealed by Sportsmail last week, the Dutch midfielder suffered a calf injury after returning from New Zealand last month and has not featured since.
Newcastle signed De Jong to bolster an attack that finished in the middle of the pack last term. He scored seven goals in 19 Dutch Eredivisie appearances for Ajax, but also missed time due to injury, which makes his quick absence following the move even more concerning.
At the same time, clubs are usually far more willing to play it safe with players at this stage than they would be later in the campaign. It could be an instance of the club just trying to avoid a more serious injury that could sideline him for a longer period.
Lee Ryder of The Chronicle passed along comments from Pardew, who currently expects to take the pitch next week against Aston Villa:
Once healthy, he figures to provide an attacking presence Newcastle lacked recently, especially during the second half of last season. Damian Buxton of Squawka provided his outlook for one of the side's marquee additions:
Given Newcastle's disdain for spending money in recent years, De Jong's signing can only be a positive. If he can reprise his Dutch form then he could be a bargain and add much-needed attacking force to Newcastle's midfield, finally going some way to replace [Yohan] Cabaye.
It's always a disappointment when a club signs a player during the summer and they aren't ready to feature when the new campaign gets underway. The good news is that it doesn't sound like an injury that's going to keep him off the pitch for long.
De Jong flashed some terrific talent during his time with Ajax. There will be a transition period as he acclimates himself to the Premier League. Once he goes through that, he should prove himself as a key asset for Newcastle, assuming he stays fit.