Sir Alex Ferguson took Manchester United's aura with him.

Aspects of the club's identity remain unbowed, the wealth, the status, the commercial power, the place amongst the continental elite, but there was a psychological diminishment. During Ferguson's reign, the team naturally suffered setbacks, in individual games and in campaigns as a whole, but once the manager established the ruthlessness and ambition of his own personality on the club, there was always a sense of inevitability about United's resurgence.

Under David Moyes, teams sense a weakness in United. There is no crisis or calamity at the club, merely the awkward, faltering steps of a transition period. The team is vulnerable, but there were times when Ferguson's team-building was not flawless and opponents took advantage then, too. Moyes cannot fall back on the longevity of his predecessors success; there is no bulwark to the doubts and anxiety that inevitably gather around a team that lacks confidence and assurance.

This is United's weakness. After consecutive defeats in the Barclay's Premier League, against Everton and Newcastle United, they sit ninth in the table. They have already lost three times at Old Trafford, as many defeats at home as they suffered in the entirety of last season. The Champions League has provided respite, since United efficiently mastered a group containing Shakhtar Donetsk, Real Sociedad and Bayer Leverkusen, and the wan inconsistency of the team's domestic form did not disrupt their results.

Moyes has at least defied some expectations, since it was in Europe a struggle was anticipated. He has little Champions League experience, but United's opponents did not seek to exploit the mental weaknesses domestic rivals have targeted. At Old Trafford on Tuesday, Moyes's side was untidy and lacked authority in the first half, but took command after the interval, and following some harsh words from the manager.

Individual matches can carry their own struggles, but United's consistent toiling this season tells both of the struggles that Moyes faces and the extent of Ferguson's influence. This remains, in essence, the team that won the title last season, and while opponents had their own problems to contend with then, there is a similar lack of outstanding virtue in any of the teams vying for this season's crown.

Moyes needs to upgrade every area of his team, and even the business of last summer was a fillip to opponents. United set out to sign top-rank players, particularly in midfield, but could not conclude any deal until they bought Marouane Fellaini - for a larger price than if they had moved more swiftly - towards the end of the transfer window. With few leading players moving at anything other than premium prices next month, United will in effect need to contend with their squad as it is. Leighton Baines may move from Everton, but it is in central defence where United are at their most infirm, with Rio Ferdinand in particular looking drained of his imperiousness.

An accomplished midfielder is also required, as well as the means to fit Wayne Rooney into the attack along with Robin van Persie without exposing other weak areas. There has been a renaissance in Rooney under Moyes, which the manager deserves credit for, but other players have withdrawn, not least Ashley Young, Nani and Antonio Valencia. Moyes needs to overhaul the side, but also his own approach to the transfer market, as well as the club's.

United wanted to make a statement with a major signing last summer. That would have re-emphasised their intent following Ferguson's retirement, but it would also have indicated a shift in policy, since spending under the Glazers' ownership has been curtailed, at least in relative terms. Moyes tends to dwell upon targets, analysing and contemplating, so that much of Everton's work was carried out during the latter stages of transfer windows. He will not spend money lightly, but next summer requires swiftness and decisiveness.

By then, Ed Woodward, the United vice-chairman, may be better prepared for the intricacies of the transfer market. As well as changing their manager last summer, the Old Trafford club also underwent a shift of power in the executive management structure, with David Gill moving aside for Woodward. A period of uncertainty was inevitable, but a second season of poor form will damage Moyes much more severely than troubles during this initial campaign.

Europe may yet provide a riposte to the doubters, since a run of good fortune can carry teams far in the competition, and United still possess world-class players. Nonetheless, Moyes is troubleshooting right now, and if the domestic form does not improve then even qualifying for next year's tournament will become a stress for United.

The manager will take time to assert a new era. He needs to build a new team, but the club will not countenance a period of decline. United's strength is its financial power, and the commercial deals it has amassed, but that income relies on United being amongst the elite. The Champions League has been accommodating to Moyes, but only so far.