The 66-year-old believes his side are "short of quality" and will require wholesale changes if they are to compete next season after suffering their 20th defeat of their campaign
Redknapp’s side took the lead through a Loic Remy penalty but then went down to a spot-kick from Hatem Ben Arfa and a fortuitous winner from Yoann Gouffran.
|5/1||QPR are 5/1 with BetVictor to win the Championship next season
“That team today wouldn’t finish in the top half of the Championship,” Redknapp told reporters. “How do you know who’s going to go? You need to shift people; you can’t just keep bringing people in.
“It’s difficult shifting players but you can always shift a few that other teams want. Shifting the ones you want to get rid of is always difficult.
"It’s down to a lack of quality, not character, not work-rate. They are just short of quality. We haven’t got a lot of quality in the team, they are not good enough.
“We have to do something about it. It will be a very difficult job [in the summer].”
Jose Bosingwa was at fault for both of Newcastle’s goals and was the subject of consistent booing from the home crowd, but Redknapp – who took the Portuguese full-back off at half-time – refused to fully blame the 30-year-old for QPR’s defeat.
“We conceded two bad goals – they were horrendous, really,” the 66-year-old continued. “He [Bosingwa] didn’t make mistakes purposely. He made a couple of mistakes but not because he wanted to. I’m not blaming him entirely.
“I took him off because you need the crowd to be behind you when you’re chasing the game.
"People pay their money and we all get grief at some stage – managers, coaches, players. The fans obviously decided they were not happy with him.”