Prince William has been visiting Premiership side Charlton Athletic to prepare for his role as the new Football Association president.
William, 23, met and trained with players and youngsters at Charlton's practice ground in south London.
Aston Villa supporter William, who spent some time in goal, is due to take over the FA presidency in May.
After visiting Charlton, he told reporters: "I want to be a contributor, I don't want to be just a figurehead."
He continued: "I want to help the guys and... just generally support football in every way I can."
The prince, who will follow his uncle, the Duke of York, in the president's role, added the training showed him he was not as fit as he thought he was.
He wore his Eton house colours of royal blue and fawn as he stood in goal.
William saved three attempts but let in four balls kicked by children from the club's community programme.
The youngsters called out "dodgy keeper" to the man second in line to the throne.
He was presented with a red Charlton football shirt with "Wales W" and "2" on the back.
Ahead of William's visit, Charlton manager Alan Curbishley - the second longest serving manager in the Premier League - had warned the prince would be put through his paces.
Mr Curbishley said: "Being landed in south London with a group of people that he perhaps doesn't know too much about, we will try to let him enjoy himself.
"If we can get a pair of boots that fit him we will see what he's got."
He added: "He looks like someone who likes to stick the ball in the back of the net."
Charlton Athletic, which is currently second in the Premiership, is considered to have one of the best community-based training programmes in the country.