The coaches of Uruguay and Ghana have brushed aside conspiracy theories claiming English referee Howard Webb was replaced as the man in charge of Friday's World Cup quarter-final because of the controversy over Frank Lampard's disallowed goal.

A Uruguayan referee team led by Jorge Larrionda was in charge of the England v Germany match when Lampard's shot clearly crossed the line but no goal was given.

FIFA on Thursday announced Portugal official Olegario Benquerenca will take charge of the Uruguay v Ghana quarter-final and insisted there was no question - as has been rumoured - that Webb, who has not been given a last-eight match, had originally been earmarked for the match.

Uruguay coach Oscar Tabarez said: "It seems every time there is a slight coincidence of any sort we start to dramatise things.

"We have nothing to do with refereeing - they are like a player and they can do well or do badly, we don't have any suspicions, it does not exist as far as we are concerned.

"I don't know if my players even know who the referee is. I presume the four officials we will have will be great candidates for the final."

Ghana's coach Milovan Rajevac added: "I pay no attention to who will be our referee - it's the highest level of competition and the referee will be of the highest level. After a match I never make comments about the referee so I'm not even thinking about it."

Uruguay only qualified for the finals through a play-off but have been one of the surprises of the tournament under their vastly experienced 63-year-old coach Tabarez, known to all as 'Maestro'.

Reaching the semi-finals would be the best achievement by the first winners of the World Cup - Uruguay triumphed in 1930 and then again in 1950 - since 1970, but Tabarez has warned against looking back at past glories.

He added: "I don't want to look back and talk about the historical dimension - anything that involves thinking beyond Friday makes us lose concentration. Perhaps later on we will be able to talk about the historical significance.

"First we have to play this quarter-final against Ghana and they are very strong."

Ghana striker Asamoah Gyan claims he is not surprised to be one of the stars of the World Cup.

The Rennes player has scored three goals in four matches including the winner against the United States in the last 16.

It is a far cry from two years ago, when Gyan was close to quitting the African Nations Cup after being criticised by the Ghana supporters.

Now the 24-year-old, who has recovered from an ankle knock, has his sights set on playing in the Barclays Premier League.

Gyan said: "I did expect to score goals here because I did so well for my club and the confidence is there. I've scored many goals for my club.

"I am not surprised to be a star here. I know what I am worth when I am 100% fit. I thank God for that.

"People compare me with big names like Lionel Messi and I'm very happy to hear that. They are the best strikers in the world.

"You also have to remember that two years ago I was criticised by my compatriots.

"It hurt. But I never lost trust in myself. I knew that when 100% fit I would perform and that is what has happened."

Gyan admits a laid-back approach - including a bout of singing - has helped Ghana become only the third African nation after Cameroon and Senegal to reach the last eight of the World Cup.

He said: "Uruguay are a difficult side but we don't care who we are going to play against. We are ready to play anyone.

"I don't think that is a problem. We shall go there and play our hearts out and we will come out victorious.

"We know all of Africa is supporting us. We are the only African team left and we want to make everyone happy.

"We know how to psych ourselves up before the game. That is the key to our success.

"Sometimes we sing all the time, we just forget about the game, and make sure we consider it on our terms because we know what we can do on the field."

As for his own future, Gyan admitted: "It is my wish to play in the Premier League but I am now a player of Rennes and I am concentrating on my club and also the World Cup.

"We will see after the World Cup."

Ghana will be without Jonathan Mensah and Andre Ayew, who are suspended, but Isaac Vorsah returns after missing the last three matches with injury.