Steve McClaren's side were beaten 5-1 by Palace on Saturday.
Steven McClaren’s side are now 19th in the table in the table, after being drubbed 5-1 by Crystal Palace on Saturday afternoon.
It was another disappointing display from the Magpies, who have failed to get going under McClaren so far this season.
They are now two points from safety, with rivals Sunderland moving above them after their win over Stoke City.
And Harper is worried things could get worse as the season heads into the crucial Christmas period.
Very harsh & by the sound of it justified words on the radio tonight about the Newcastle display. Worrying times given the fixtures ahead!!— Stephen Harper (@steveharper37) November 28, 2015
It is easy to see where the former keeper is coming from, with them set to face Liverpool, Tottenham and Everton in the coming weeks.
They also come up against Aston Villa, which is sure to be a tough challenge, with the Villans currently bottom and keen to start picking up points themselves.
Defeats in those games could see them cast adrift in the bottom three, with Sunderland in particular now starting to pick up points above them.