The Duke of Cambridge has said he is "dying" for Leicester to win the Barclays Premier League title.
William, presented with a special cap during a Wembley Stadium lunch on Wednesday to mark his 10 years as president of the Football Association, threw his support behind Leicester's bid to secure the title.
At a reception held before guests sat down to eat, the Duke commented on the Foxes' impressive run of form which has taken them to the top of the table and told FA board members: "I'm dying for Leicester to win."
William's own team Aston Villa are on the brink of relegation from the top flight and he hinted that his thoughts were on his club playing in a lower division next season.
FA board member Ian Lenagan, a director of Oxford United, said later of William's comments about Leicester: "He felt it would be good for football - it would be great for the game."
He added: "He's rather more worried about the prospect of Championship football from his own point of view."
In a speech to mark William's milestone, FA chairman Greg Dyke joked how the Duke, who still plays football with pals, brought a friend to his regular game - David Beckham.
Dyke told the guests, who included England manager Roy Hodgson: "He cares about our development, about what we're doing to get a common thread between youth sides and the senior set-up, and how we're building our support staff.
"He doesn't just listen, he asks a lot of questions and always has a clear point of view. He brings his own experiences to bear, whether that's from his range of other professional roles, or from just being a football-loving dad of two, who still gamely plays the game himself.
"Rumour has it that he occasionally uses his connections to help his team. One week he turned up to his regular six-a-side match, so we're told, and brought a friend to join his side - the friend was David Beckham."
Highlights of William's tenure as president have seen him help organise a competitive game at Buckingham Palace between two of England's oldest amateur clubs, Civil Service FC and Polytechnic FC, as part of the FA'S 150th anniversary celebrations in 2013.
He also played a role in England's bid to host the 2018 World Cup, joining a delegation in Switzerland in 2010 which included David Cameron and David Beckham, but it ultimately failed.
And in 2012 the Duke and his wife Kate opened St George's Park - the ?105 million national centre of football excellence in Staffordshire.
Former Chelsea and Aston Villa defender Paul Elliott, a member of the FA's Inclusion Advisory Board, chatted to William about the footballing exploits of his daughter Princess Charlotte, who appears to be outshining older brother Prince George.
Runs in the family
The Duke said of his 11-month-old daughter: "She's a very good footballer - you hold her hand and she kicks. Very sweet."
Elliott said: "He said there were encouraging signs about his young daughter - and he's encouraging George to keep practising."
William, who took over the presidency of the FA in May 2006 from his uncle the Duke of York, appeared to publicly back outgoing chairman Greg Dyke's efforts to reform the FA Council by making it more representative and diverse.
Mr Dyke is pushing for an end to the traditional "blazers" who dominate the council, with more women, more fans' representation, more people from ethnic minorities and possibly term limits to reduce the average age.
The Duke told the guests: "There is one area in which I feel we do still need to improve and to do so with some urgency.
"Our governance structure is in danger of falling short of modern standards of best practice.
"There is a wind of change blowing through global sporting governance and we need to ensure we do not get left behind. In fact, as the country's national sport, we ought to be leading the way.
"I know the organisation is currently reviewing this issue and there is an opportunity to seize the initiative by the way in which we reform ourselves. This is an emotive issue, and it is one that you all have a stake in deciding."