Jack Colback has labelled Newcastle's performance in the 5-1 defeat at Crystal Palace as "embarrassing".
Yannick Bolasie and James McArthur both struck twice as Palace cruised to victory at Selhurst Park on Saturday, inflicting Newcastle's seventh defeat in 11 league games to leave Steve McClaren's position under intense scrutiny.
Colback started in midfield for the Magpies and he told his club's official website afterwards: "We had a game plan and in the first 15-20 minutes it worked perfectly. We got the goal and you could see they were rattled.
"But we let them straight back in, then I made a mistake for the second goal and that put us on the back foot again. After that it was pretty embarrassing, really.
"Maybe we're not strong enough character-wise. It seems as if as soon as things go bad, it goes really bad.
"We had that last year and probably the year before as well. It's something that's hanging over the team that we need to get rid of.
"We had shown signs of improvement but the Leicester game and this one have really set us back quite a lot."