By Phil Harlow

Kenyon joined Man Utd in 2000

When the transfer window closed on 31 August, even the most optimistic Chelsea fan could not have anticipated that the biggest capture of all was just around the corner.

After spending more than �100m on a host of Europe's top stars, Chelsea - bankrolled by billionaire Russian owner Roman Abramovich - have upped the ante on their Premiership rivals by grabbing Manchester United chief executive Peter Kenyon.

The move signals a massive statement of intent from the west London club.

They are prepared to take on the established hierarchy of English football on every level - on the football field, in the transfer market and now, in the boardroom.

Man Utd chief joins Chelsea

Kenyon's detailed knowledge of Old Trafford's inner dealings - wage structures, plans for commercial expansion, possible future transfer targets - is now in the hands of one of their strongest competitors.

It is a worrying development for United, who have dominated the Premiership since it was formed in 1992 but now find themselves threatened by a rival with huge financial clout.

Profile: Peter Kenyon

Man Utd wasted little time appointing managing director David Gill as Kenyon's successor.

But Kenyon's smooth - and highly profitable - running of affairs is a tough act to follow at a club used to success on and off the field.

He orchestrated deals with Nike and Vodafone that brought in huge revenues and continued the club's extension into the lucrative Far East market.

As a PLC, Man Utd will also have to consider the possible effect on its share price of losing a highly-valued operator at such an inopportune time.

And Man Utd may also start to worry about their well-established image and reputation as one of biggest clubs in the world.

Abramovich has shaken up the Premiership

Chelsea do not operate under the same financial constraints as those that govern Man Utd.

But the news of Kenyon's defection to Chelsea does not just raise questions at Old Trafford but also at Stamford Bridge.

The Blues' current chief executive Trevor Birch could have been forgiven for thinking that he had just completed a successful summer's work since Abramovich took over.

Given a list of players to recruit, Birch has been conspicuously successful in attracting the likes of Herman Crespo, Joe Cole and Juan Sebastian Veron.

But the news of Kenyon's arrival as chief executive of the "Chelsea group of companies" casts doubt over Birch's status.

Then there is the question of when Kenyon will arrive at Stamford Bridge - according to his Man Utd contract, he must go on a spell of gardening leave before joining another club.

And how will Kenyon adapt to working to the whims of a single - and very wealthy - owner as opposed to a wide range of shareholders?

Whatever the implications, Abramovich's audacious move for Kenyon is more than just a flexing of muscle by a new owner determined to prove he means business.

In stark terms, it demonstrates Chelsea's absolute determination to confront Man Utd, and the rest of the traditional footballing elite, using massive financial clout as their most potent weapon.