Gary Neville believes QPR's 'weak' defence could end up costing the Londoners their Premier League status.
Harry Redknapp's charges were conquered 3-2 by west London rivals Fulham on Monday evening following a catalogue of rearguard errors and are now seven points from safety with just seven games remaining.
No club in Premier League history has stayed up having been in that position and Sky Sports pundit Neville reckons Rangers, who battle fellow strugglers Wigan on Super Sunday, are unlikely to be the first.
"There were terrible mistakes in the first part of the game with Fulham which have cost them," said the former Man United man. "You can point to missed chances, particularly Loic Remy's missed penalty, but ultimately the defence couldn't stand firm.
"That's always the fear with QPR; you look at the back four and you see weaknesses in the air, in terms of mobility and in coping with balls in behind them and the protection they get from midfield isn't the best, either.
"They probably have the best array of attacking talent in the bottom half but you wonder whether they can be brought together and keep clean sheets as they look like they are going to concede goals every time they play."
Chris Samba, who signed from Russian outfit Anzhi Makhachkala in a big-money deal during Janaury, had a night to forget at Craven Cottage as the visitors slipped 3-0 down inside the first half.
The Congolese fouled Fulham winger Ashkan Dejagah to allow Dimitar Berbatov to open the scoring from the penalty spot, and then lost possession on the edge of his 18-year box to the Bulgarian who tapped in to double Martin Jol's side's lead.
Neville also feels the 29-year-old was partly to blame for the Cottagers' third, a Clint Hill own goal after 41 minutes, and reckons the litany of blunders the Rs made at the back will severely damage their confidence ahead of the crunch game with Wigan.
On Samba, who apologised for his performance on Twitter after the match, Neville said: "He is a good centre-back who has been brought in because he is reliable, trustworthy and a leader at the back but he had a really difficult period in that game.
"There is no excuse for the penalty that he gives away in which he got caught out of position and then fouled Dejagah, while for the second goal he has plenty of time to sort his feet out and, for the third, he allowed Damien Duff to run down the side of him.
"The effect of giving away bad goals is terrible on any team; it creates an uncertainty at the club and in the crowd every time the opposition attack, so that is a real problem for QPR
"I've always maintained that because of the run-in QPR have and the fact they have got Redknapp as manager, someone who has been there before and done it at Portsmouth, they could stay up.
"But the games you thought they would pick points up from, the likes of Aston Villa and Fulham, are going and if they don't beat Wigan they are probably gone - and even if they do that it will still be tough.
"They need to pick up three wins from their next four games (against Wigan, Everton, Stoke and Reading) and maybe even three wins and a draw, so that they give themselves something to play with before the final three games against Arsenal, Newcastle and Liverpool."