It's an unlikely fact that Stoke, Sunderland, West Ham and West Brom have all conceded far fewer league goals so far this season than Manchester United.
Having picked the ball out of their own net nine times in six Premier League games, it's fair to say Sir Alex Ferguson's side are having a shocker at the back this campaign. Only the bottom seven sides have conceded more goals, with Manchester United letting in three times as many as league leaders Chelsea.
In fact, they've kept just two clean sheets in all competitions, even managing to go behind to another early and sloppy goal against CFR Cluj in this week's Champions League encounter.
It's certainly not what we've come to expect of Ferguson's sides over the years - Peter Schmeichel would not be impressed.
But after an opening day defeat to Everton and subsequent warnings from Fulham and Southampton, they've yet to resolve the problem and last weekend's loss to Tottenham - the first at Old Trafford in 23 years - has left them four points off the pace in the Premier League.
It's a real possibility that, despite the attacking threat of Robin van Persie and Wayne Rooney, that Manchester United's defence could cost them the title - although they still remain [3.55] to win the Premier League this season, second favourites to their city neighbours.
Regardless of what anyone thinks of the Rio Ferdinand England situation, few could claim he is the player he once was and he is starting to be found out, most recently by Gareth Bale last weekend. A similar accusation could be levelled at Patrice Evra.
But with Nemanja Vidic, Phil Jones and Chris Smalling all in the treatment room, there's no obvious, immediate remedy to the situation.
And they face another tricky encounter when they travel to Newcastle on Sunday, despite being strong favourites at [2.0] for victory, with the hosts [4.1].
Magpies' forward Demba Ba is currently the Premier League's top scorer with six goals, ahead of Van Persie, Sunderland's Steven Fletcher and Liverpool's Luis Suarez on five, so Ferdinand and co. won't be enjoying an easy Sunday afternoon.
Despite their trials, Manchester United's model is one the north-east club want to follow and last week decided the best way to do so was to offer boss Alan Pardew and his coaching staff eight (yes, eight!) year contracts at St. James' Park. It could either be madness or a masterstroke.
Newcastle had a superb season last year as they finished fifth, narrowly missing out on a Champions League spot, but are at [4.5] for a top six finish this time, behind the likes of Liverpool, Everton and Chelsea, who all finished lower than the Magpies last campaign.
And without a limitless pot of gold to play with, Pardew has certainly done well on Tyneside, not only in terms of league position but also in restructuring the club's transfer policy - letting big earners go and bringing in relatively cheap foreign imports such as Papiss Cisse and Yohan Cabaye.
Certainly, most Newcastle fans would appreciate owner Mike Ashley's desire for stability, especially as he's been through seven managers since he bought the club in 2007. But whether a four-year contract and the ability to relieve Pardew of his duties should anything go awry would have been sufficient remains to be seen.
Either way, Sunday could be Pardew's first step towards emulating Sir Alex Ferguson's success and the journey could begin by beating Manchester United in the process.
Newcastle and Manchester United to draw on Sunday at [3.8]