Pro boxing’s unified heavyweight champion Anthony Joshua is one of the biggest draws in combat sports today.

Unbeaten in 21 fights since joining the paid ranks following his 2012 Olympics gold at super-heavyweight, AJ defends his world titles against WBO mandatory challenger Alexander Povetkin in his latest bout at Wembley.

On form lines through former champ Wladimir Klitschko who Joshua dethroned in 2017, it’s no wonder he is a red-hot favourite according to the heavyweight boxing betting odds available with William Hill to defeat Povetkin, with the Russian a big outsider to take the WBA (super), WBO, IBF and IBO belts.

What if AJ were to swap a boxing ring for the octagon one day, though? Former UFC featherweight and lightweight champion Conor McGregor did the reverse, famously donning pugilists gloves to fight Floyd “Money” Mayweather, albeit unsuccessfully.

We so often don’t get to see what-ifs like that. Should Joshua ever decide to take up MMA, then which fighters can he learn from? Here, we take a look at three examples to follow or avoid.

Brock Lesnar

As the only man to win the NCAA heavyweight championship in amateur wrestling, WWE world heavyweight championship and UFC heavyweight championship, Brock Lesnar is arguably the most successful combat sports athlete ever. He’s definitely one for AJ to take notice of if he steps inside the octagon in the near future as Lesnar is making a second return to MMA.

The Beast Incarnate defeated Randy Couture in just his third UFC fight to become the heavyweight champ of the sport, proving you can make quick adjustments from one discipline to another. Lesnar is training for his MMA comeback but also continues to wrestle, having dropped the WWE Universal Championship to Roman Reigns at SummerSlam.

Holly Holm

Before she became known as the first woman to beat Ronda Rousey inside the octagon, Holly Holm was widely considered one of the best female boxers of all time! Competing mainly at welterweight, she won a host of championships and boasts an impressive 32-2-3 record in the squared circle.

Given her amateur kick-boxing background, Holm was already adept at switching between combat sports but her MMA career was launched into the stratosphere by that monumental upset of Rousey at UFC 193. Although she’s won just two bouts inside the octagon since, the lesson for Joshua here is upsets do happen and other fighters can make a name for themselves at a star’s expense.

CM Punk

Not every combat athlete makes a successful transition between disciplines, however, and former pro wrestler CM Punk is an example of that. Unlike fellow Paul Heyman guy Lesnar, Chicago native Punk lost both of his MMA fights after leaving the WWE.

UFC president Dana White has said he probably won’t compete inside the octagon again, but certainly made the most of the spotlight with the sixth-longest WWE Championship reign in the promotion’s history between 2011 and 2013. Punk’s is clearly a tale AJ wants to avoid emulating in any way should he ever swap boxing for cage fighting.