With Wayne Rooney leading a feared forward line, it is easy to forget that Manchester United's championship success last season was built on their defence. The partnership of Rio Ferdinand and Nemanja Vidic - a seemingly perfect blend of power, pace and positioning - was irresistible as they conceded just 24 goals, the same amount as Chelsea, in the campaign.
Injuries and suspension have deprived Sir Alex Ferguson of their services for much of this season. For only the fourth time - and the first since a 2-0 defeat at Liverpool in October - the United manager will have his first-choice pair available. And, for all his side's attacking strength, it could not be more timely. A resurgent West Ham visit Old Trafford tonight before Sunday's match against Aston Villa in the Carling Cup final.
The defeat at Everton on Saturday was another warning for Ferguson that despite the promise of Jonny Evans and willingness of Wes Brown, they are no match for the Ferdinand and Vidic axis at the back. Having lifted themselves out of relegation trouble with successive wins against Birmingham and Hull, the happier Hammers now offer a greater threat. The takeover by the two Davids, Sullivan and Gold, has undoubtedly helped. Threats of administration and pay cuts, if relegated, have raised performances.
Players like Julien Faubert and Valon Behrami have started to justify their combined £11 million (Dh62m) price tag and potential. Then there is the return of Carlton Cole after a knee injury. In October, he helped confirm England's place in the World Cup finals. But with the increasing competition for places in Fabio Capello's England squad, including from the unlikely figure of Fulham's Bobby Zamora, Cole still requires peak performance to ensure he is in South Africa.
Goals against Birmingham and Hull will have gained the attention of Capello, the England coach, but Cole said: "I'm getting games following my injury, but I don't think I played that well, by my own standards." Gianfranco Zola, his club manager, does not agree. "You can see when he is in the team, we always pose a threat," he said. "But he also affects the team defensively. "Carlton is such an important player for us. He gives the team a different dimension."
That is something Rooney has given United too, but his manager still has a conundrum regarding the frontman. Recent displays suggest he works better alone. Yet six of Rooney's 10 goals in the last nine games have come with Dimitar Berbatov or Michael Owen alongside him. Their presence takes some of the workload and defensive attention away from the England man. Berbatov did that against Everton with a well-taken goal, but Rooney was a shadow of the forward who was magnificent in the 3-2 win over AC Milan last week.
Like his defence, Ferguson has to make the right choices to help United reduce the deficit on leaders Chelsea to one point again.
"'The league has been wide open this season; it's been funny like that," he said. "Teams have dropped points you don't expect them to drop, but the very nature of the league suggests we still have a good chance."