Sonny Bill Williams brutalized by Tyson Fury during medicine ball training drill

Two-time heavyweight champion Fury has been posting training clips with New Zealander Parker, showing the pair body sparring alongside the Rugby World Cup winner.

Heavyweights Fury and Parker have struck up a close friendship during their boxing careers and are again training together ahead of their respective returns to the ring.

However, training took a nasty turn when the medicine ball was taken out, with the boxing stars laying into each other.

Where else to start? The 35-year-old multi-sport athlete has confirmed his retirement from all forms of rugby earlier this year as he plots a return to boxing, full-time.

Williams has fought professionally seven times — most recently in 2015 — and won seven times, with three career knockouts.

The England forward played several other sports in his youth, including basketball, football, and athletics. However, he represented and starred for England at U17 level in Shot Put and was on course to be an Olympian before ditching the heavy round ball for an oval one full time.

DID YOU KNOW? So far in his rugby career, he has won four English Premiership titles with Saracens, three European Rugby Champions Cup titles, and four Six Nations Championship titles

Price, a former rugby union and rugby league professional, cemented his place in sporting history by winning the 2021 PDC World Darts Championships at Alexandra Palace back in January

Having played as a hooker for Welsh Premier Division outfits Neath and Cross Keys, he played for South Wales Scorpions in rugby league as well as a short spell as cover with Pro12 side Glasgow Warriors.

A Canada international in rugby union, both in 15s and sevens, and a 2x winner of a gold medal at the 2010 Winter Olympics in two-woman bobsleigh.

The future World Cup winning England captain briefly played American football in the early 1990's for the Leicester Panthers, his local American football team as a tight end or defensive end, but he didn't consider taking it any further.

Johnson said: 'I'd never be quick enough. In our sport, you try to get good rugby players and make them into athletes. In the NFL they've got some good athletes who they make into players. How quick you do the 40 [run 40 yards] is the big thing. "What? He does the 40 in 4.2? He's that quick?" They love their stats.'