Gary Neville thinks Manchester United's defence lacks "control" and consistency.
United may be on course for Champions League qualification, their defensive vulnerabilities have been exposed on many occasions this season and they have relied heavily on the excellent form of goalkeeper David de Gea.
United concede an average of around a goal a game and have the fewest number of clean sheets in the top five.
Chris Smalling, Phil Jones and Jonny Evans have born the brunt of criticism, but Neville feels they will improve if their injury problems subside.
"With the likes of Smalling, Jones and Evans we still have great hopes for that penny to drop," the former United captain told fanzine Stretty News.
"They're still developing and picking up injuries but when they stop and the penny drops you think: 'We've lived with his faults, development and now we're getting the benefit of it.'
"There is no doubt that Jones, Smalling and (Luke) Shaw have talent but they need experience, maturity and injuries to stay clear and they will fly."
QPR 0 Manchester United 2 player ratings
QPR 0 Manchester United 2 player ratings
1/27 Rob Green - 5/10
Couldn’t be blamed for letting Fellani’s powerful effort in, but spilled a save into the path of James Wilson to give away the second.
2/27 Mauricio Isla - 7
Wasn’t really tested down the left but got forward well and delivered some nice crosses. Once United went ahead he was a constant threat in the QPR attack.
3/27 Nedum Onuoha - 6
Composed on the ball for the most part and outmuscled the United attackers. Caught out of position as his team searched for an equaliser.
4/27 Richard Dunne - 6
The centre-back looked solid before being subbed at half time.
5/27 Clint Hill - 6
Looked good until QPR were forced to attack in the second half which pulled him out of position.
6/27 Edurdo Vargas - 7
Had a lively game, winning possession and creating chances on more than one occasion.
7/27 Joey Barton - 5
Lucky not to give away a penalty for a cynical block on Wayne Rooney in the first half. Delivered set pieces well.
8/27 Karl Henry - 5
Helped provide pressure in the middle. Dropped back and helped frustrate United for long periods.
9/27 Leroy Fer - 6
Played a part in the QPR attack, winning headers and moved the ball about well enough. Subbed on 70.
10/27 Charlie Austin - 7
The Premier League player of the month was constantly threating a vulnerable United defence. Twice forced de Gea into good saves and was unlucky not to score.
11/27 Bobby Zamora - 6
United dominated possession which left the big man starved of chances. Fought for the aerial ball well as expected. Subbed on 70
12/27 Steven Caulker - 5
Was forced into the attack as QPR chased from behind and couldn’t make anything happen.
13/27 Adel Taarabt - 7
Was part of everything that QPR did following his introduction and helped trouble the United defence.
14/27 Niko Kranjcar - 6
Wasn’t unable to effect the result after his late introduction.
15/27 David De Gea - 8
If United do qualify for the Champions League they’ll have de Gea to thank for it. Made some fantastic stops early on and quashed a number of QPR attacks in the dying minutes.
16/27 Phil Jones - 5
Looked nervous early on and made some errors, but he helped withstand the late QPR onslaught.
17/27 Jonny Evans - 5
Didn’t look particularly assured before he was subbed for James Wilson.
18/27 Marcus Rojo - 6
Was embroiled in a physical battle with Bobby Zamora and fared well. A strong performance from the Argentine.
19/27 Antonio Valencia - 5
Has been effective breaking away down the right flank in recent weeks but he didn’t look dangerous today.
20/27 Michael Carrick - 4
Anonymous for the second straight game.
21/27 Juan Mata - 5
His passing, normally so effective, was errant at times and didn’t create any good chances. Subbed at half time for Fellani.
22/27 Daley Blind - 6
Couldn’t stop Mauricio Isla from having some success down the left but picked out a few nice passes as United went forward.
23/27 Wayne Rooney - 7
Largely shut out of the game in the first half, but played a crucial part in most of United’s attacks including the goals.
24/27 Angel Di Maria - 5
A lot of running, but doesn’t look like he enjoys playing up front. Can’t find a killer ball but it’s not from lack of trying.
25/27 Radamel Falcao - 6
Was poor in the first half but grew into the game in the second. He couldn’t get on the score sheet but he put in a shift and came close on a number of occasions.
26/27 Marouane Fellaini - 8
As expected, Fellani challenged every long ball and usually came out on top. Blasted his goal past Robert Green in a powerful performance.
27/27 James Wilson - 8
Energized the attack when he came on. Created two very good chances for Falcao before scoring a late second. Tenacious.
De Gea has rescued United on several occasions this season, most notably against Tottenham, Everton and Stoke.
And he showed his worth again on Saturday at Loftus Road when he stopped a fierce drive from Charlie Austin in United's 2-0 win over QPR.
The constant chopping and changing of players in front of De Gea has not helped United, according to Neville.
"When I look at the United defence what it lacks is control," said the former United defender, who now works as a Sky Sports pundit and England coach.
"I see players that have talent but they're all individually working, not having controlled movements together of in-sync. That comes through understanding and from playing together.
"The reason that Chelsea have the best back four in the league is because they have good players, they play every week without many injuries.
"United have been absolutely blitzed with injuries in those positions for the last three years.
"At times they look all out at sea but you have to say in Louis van Gaal's defence, he has had Darren Fletcher in defence, Michael Carrick in defence with Antonio Valencia and Ashley Young as wing backs that have done well."
Neville seems to think United have the right manager to bring back the kind of glory days he enjoyed at Old Trafford, describing Van Gaal as "a great coach".
And he thinks the Dutchman has the perfect midfielder to orchestrate United's play in Michael Carrick.
Neville believes it is no coincidence that United have lost just once since Carrick returned from a serious ankle injury he suffered last summer.
"At the start of the season we were struggling, ask yourself who wasn't playing? Michael Carrick wasn't playing," said Neville, who played 602 times for the club.
"Now he's playing and the club went on a great unbeaten run.
"When you play with Michael Carrick you think there is authority, control, peace.
"When you are on a football pitch playing against Liverpool or Manchester City, you need peace around you as well. You sometimes don't want people running around.
"Scholes and Carrick together was peaceful. It was like going into a bar and hearing a piano playing.
"It's relaxing. Listening to some good rock is good and you like that too but sometimes it's nice to listen to a piano. Carrick's a piano."
- More about:
- Manchester United