It is possible for the Blades and Wigan, who play each other at Bramall Lane, to stay up if West Ham are defeated at Manchester United and Sheffield United also lose.

Conspiracy theories have been floated because Sheffield United and Wigan have been the leading members of the 'Gang of Four' clubs threatening legal action against the Premier League for failing to dock points from West Ham for contract irregularities over the signing of Carlos Tevez.

But Magnusson said: "It has never even entered my mind that such a thing would ever happen in English football.

"The personalities involved are far above that kind of thing and it is not something I would ever worry about.

"The three teams involved in this relegation battle will all be trying to win their match on Sunday and, again, that is the only way football should be."

The Icelandic businessman said relegation should be decided on the pitch.

Magnusson added: "We have experienced a lot of publicity, especially since the Premier League hearing, but it has not affected our focus and concentration ahead of the matches, and that is the most important thing.

"Two weeks ago, we had a judgement which resulted in a severe fine for the club. This week, we decided not to appeal against it, and that is the end of the whole matter as far as I am concerned.

"We have worked very closely with the Premier League, who have also confirmed that the matter is closed, and so there is nothing more to be said.

"I feel very strongly - as I hope all football people do - that the matter of who wins the championship, who is relegated, should be decided on the pitch. That is the only way for football to be the winner."

Magnusson believes that even if West Ham were relegated he made the right decision to invest in the club.

He added: "Whatever happens at Old Trafford, I am committed to taking this club forward and building on the plans that we have put in place. I am here for the long haul.

"Despite all the turbulent times that we have experienced at the club this season, I can honestly say now that I am even more certain I made the right decision in taking the opportunity to become involved at West Ham United.

"The tremendous support and fan base we have assures me that our future is a bright one. I have been here for only five months, but my love for this club is already well established."

Magnusson also made clear that come what may on Sunday he will be keeping faith with Alan Curbishley as manager.

He said: "Alan Curbishley, his coaching team and the players have done a fantastic job, and now we just need one final push to see us through.

"I have spoken to Alan this week, as I always do, just to see what is happening, if there are any injuries, and how things are going.

"We speak regularly and it is often just a friendly chat about football, and nothing is different this week.

"I am very confident that we can get the result we need. The team has been playing very well recently, with lots of confidence and determination, and everybody is optimistic about our chances.

"At last, the situation is in our own hands, which hasn't been the case for the last five or six months.

"Everyone is concentrating on the game, and planning what we have to do in order to combat Manchester United.

"It will be a tough task because they are a fantastic team and worthy champions of the Premier League this year, but we are playing well enough at the moment to get a result."