After the nervous laughter settled down, James Haskell realised the proposition to sign him up as a professional mixed martial arts fighter was a serious one.

Haskell only called time on his 17-year professional rugby union career in May but has dived straight back into elite sport after agreeing a deal with MMA promotion Bellator.

The 34-year-old has 77 England caps under his belt but admits when the time comes to step into the cage next year - with a date for his debut still to be decided - he will be scared.

"Mike Tyson said it: Everyone has got a plan until you get hit in the face. But for me it is a test, it's a journey," said Haskell.

"I'm not messing around with this. There has been overwhelming support but some people think it's a bit like a scene out of Rocky III.

"I'm dedicating my life to this. I want to make sure I am in the best possible shape and whatever happens at the end of it I am going to put as much dedication into this as I did into rugby.

"I'm deadly serious about it. I don't want it to be the case where I get into the cage and I look like I've never taken a punch before, it looks like I'm just here for fun. I'm not about that."

'My wife looked at me like I was mad'

Haskell is not new to MMA. The ex-Wasps and Northampton Saints flanker first started working with London-based MMA gym Shootfighters a decade ago to improve areas of his game such as tackling and has previously worked as a television pundit on shows.

But the training has intensified over the past month since he got a call from Bellator to say they wanted to sign him as a heavyweight fighter.

"I thought maybe they were going to offer me some more work, then they dropped the bombshell they wanted me to fight," explained Haskell.

"Once I had stopped nervously laughing it piqued my interest. I went back to my wife, Chloe, but she didn't find it as funny. She looked at me like I was mad.

"The first thing I did was pick up the phone to the guys at Shootfighters and ask: 'What do you think of me taking this on?'. They unanimously came back and gave me their support."

Gyms, DJing and being backed by Richard and Judy

Haskell says he enjoyed some time off - with holidays and DJing among the many things to keep him busy - but missed the discipline and dedication of professional sport. Now MMA is his full-time job.

"My training and conditioning is hard and intense, but it's clever," he added. "They dictate everything. I just come in and go 'yes, coach. No, coach' and I try not to cry.

"When I left rugby and bought my first commercial gym membership it was a shock to the system. I went in there and saw people training and thought 'I've got to get out of here and get in a proper gym'."

Haskell admits the coaches at Shootfighters have "already started flogging me" but stresses he won't be doing "spinning back kicks or axe kicks if I can't do it".

"There is a lot of hard work to be done and a lot of hours to be put in, but I am excited about it," added Haskell, who expects to make his debut against a fighter of similar experience.

His decision to come out of retirement was greeted with support from his family and friends, as well as his in-laws - TV presenters Richard and Judy.

"I don't think my mum fully understands what I have agreed to do. Which is kind of a good thing," Haskell told BBC Sport.

"My dad loves anything like this. Chloe is unbelievably supportive and her folks have been incredibly supportive. Richard is great - we will see if we can get him along to a fight."

'This is no PR stunt'

But the former rugby star is keen to distance himself from the idea this is a PR stunt or merely a brief crossover into combat sports as has been seen before, such as cricketer Freddie Flintoff's brief foray into boxing.

"People keep making comparisons to me and Freddie. He was one of my sporting heroes when I was growing up and had an amazing career," said Haskell.

"I think to do this sport you have to give up your life and be pretty dedicated. A lot of people when they prepare for these fights it's like they have never been punched before.

"By the time I get in that cage, if I am still alive to tell the tale, I will have had a number of fights and will be well prepared."

The individual nature of stepping into the cage alone is one of the attractions of MMA for Haskell, who has spent a lifetime playing team sports.

"It must be very daunting being an individual sportsman," added Haskell, who dismissed rumours his training will be interrupted by an appearance on 'I'm A Celebrity' this year.

"I was only thinking during Wimbledon while I was watching Federer and Djokovic play that I wonder what it's like to be an individual sportsman at the highest level, when you have to look after yourself and don't have team-mates to fall back on?

"While I'm nowhere near their league in any aspect, I am going to see what it's like and see if I can be mentally tough enough to deal with it. I have no idea whether I will be or not."