Nick Kyrgios makes surprise offer to Kate Middleton after Wimbledon ...

Nick Kyrgios has offered to lend his tennis expertise to Kate Middleton following the Princess of Wales's return to Wimbledon on Sunday.

Kate, 42, who has stepped away from public royal duties while undergoing cancer treatment, attended the All England Tennis Club to watch Spanish reigning champion Carlos Alcaraz take on Novak Djokovic in the men's singles final. 

A patron of the world-famous club in South West London, Kate is a huge tennis fan and was warmly received by the Centre Court crowd in just her second public appearance after her shock diagnosis. 

Australian tennis star Kyrgios, known for his outlandish behaviour on court, was on punditry duty for the BBC during the Grand Slam final, and shared his delight in seeing Kate in the Royal Box.

He even took the opportunity to offer the Princess of Wales his services as a coach, arguing that he'd make tennis a lot more interesting than Swiss legend Roger Federer - whom Kate has previously taken coaching advice from.

‘Maybe I’m a little bit too volatile… but look, I’ve got a lot of time on my hands at the moment so I’m happy to coach [Kate Middleton],' Kyrgios said on BBC Sport. 

‘It’ll be more fun being coached by me than it would by [Roger] Federer!’

Kyrgios has been sidelined for well over a year with knee and wrist injuries, but fans are hopeful that the feisty Aussie will return to the men's game for the hard court season in the United States.

Nick Kyrgios has offered to coach tennis fanatic Kate Middleton

The Princess of Wales was in the Royal Box for the men's singles final on Sunday

She has previously taken tennis tips from Swiss legend Roger Federer

Djokovic has been seen practicing with his tennis bestie during the championships this summer, and provided a key update on Kyrgios's fitness after his semi-final win over Lorenzo Musetti. 

‘I can tell you a few days ago when we practiced – actually [Thursday] I think it was when we practiced – he hit a really good serve, and he said, ‘Well, I might come back at the US Open’ – so I don’t know if he was joking about it or not!’ Djokovic said.

‘But let me tell you, he’s hitting the ball as good as ever really. He’s so talented. He’s so good with his tennis.

‘I think he said that the wrist bothers him mostly with the serve, but he’s been increasing the load and the intensity and the speed.

‘He’s not going for full pace or full-strength serve, but he’s close to that. He’s close to that.’