Sir Alex Ferguson's years of experience mean he can sniff out a dressing-room problem better than just about any manager in the world – and we are not talking about the toilet pipe that burst above their heads before this game. This is far more serious than a few ruined designer suits, because the weekend draw with Sunderland provided further evidence that United no longer inspire fear in the Premier League.
Gone are the days when teams outside the country's elite viewed a visit from United as little more than the opportunity to attract a capacity crowd, who would usually witness a disciplined performance from Ferguson's side, capped off by a late winner from the likes of Ronaldo.
Sunderland had every reason to eschew the customary inferiority complex displayed against United, because manager Steve Bruce has assembled an improving side that was unbeaten in four previous games against opponents including Manchester City, Arsenal and Liverpool.
And, while United were unbeaten away from home, draws against Fulham, Everton and Bolton did not represent the start anticipated by Ferguson, who chose to rest Dimitar Berbatov, even though the striker is heading towards a two-week break because of the international fixtures.
A forward pairing of Michael Owen and Federico Macheda failed to trouble Sunderland, whose midfielders Lee Cattermole and Jordan Henderson possessed enough youthful energy to negate the influence of Paul Scholes.
At least there was an improvement in United's defence, which has been vulnerable recently in the league, Rio Ferdinand's link-up with Nemanja Vidic helping their side negotiate an awkward first half.
Bolo Zenden almost found a way past them when he struck a post, while goalkeeper Edwin van der Sar made a fine save from Steed Malbranque after Cattermole's pass exposed United's uncertainty.
The keeper was in a realistic mood after United's improvement in the second half helped them secure a point. "I think it was two points dropped and we have dropped too many points in away games," he said.
"It is good to get a clean sheet after getting one in Valencia on Wednesday, but we weren't really good enough in our offensive game to claim all three points.
"I was busy in the first half but you expect that with the way Sunderland play. They knew we had a game on Sunday and one on Wednesday and there was a lot of travelling involved getting back from Spain and getting up here.
"We were happy to come in at half-time at 0-0 and hope that Sunderland would die down a bit after half-time. In the last 15 minutes, we had a few chances but not enough to get the winner."
Ferguson's first reaction was to praise Sunderland; if it was an attempt to switch attention away from his own team's shortcomings, it failed. He cannot hide from the reality that, without a fully fit Wayne Rooney, this is no longer a team that will cause sleepless nights for their opponents. Ironically, this was an occasion when a Fergie excuse would have have been thoroughly justified, but he claimed the burst pipe which caused a 20-minute delay had little effect on his players.
Sunderland 4-4-1-1: Mignolet; Onhuoa, Turner, Bramble, Bardsley; Elmohamady, Henderson, Cattermole, Zenden (Reid, 82); Malbranque (Gyan, 82); Bent. Substitutes not used: Gordon (gk), Riveros, Mensah, A Ferdinand, Da Silva.
Manchester United 4-4-2: Van der Sar; Rafael, R Ferdinand, Vidic, O'Shea; Anderson (Bebe, 80), Fletcher, Scholes, Nani; Macheda (Hernandez, 65), Owen (Berbatov, 46). Substitutes not used Kuszczak (gk), Evra, Smalling, Gibson.
Booked Vidic, Rafael.
Man of the match Malbranque.
Possession Sunderland 56% Man United 44%.
Shots on target Sunderland 8 Man United 4.Referee C Foy (Merseyside).
Match rating 7/10.