All Black legend reveals Dementia diagnosis, aged 41

The former All Blacks tighthead prop, who played the last of his 45 tests in the shock loss to France in the quarterfinal at the 2007 World Cup, has been diagnosed with probable chronic traumatic encephalopathy (CTE). Hayman is 41.

“I spent several years thinking I was going crazy, at one point that’s genuinely what I thought,” he told New Zealand sports website The Bounce.

“It was the constant headaches and all these things going on that I couldn’t understand.”

Hayman said tests showed he had early-onset dementia and probable chronic traumatic encephalopathy – a neurodegenerative disease.

The diagnosis prompted him to join a lawsuit brought by similarly affected former players, including England’s Steve Thompson and Alix Popham of Wales.

The basis of the players' claim is that rugby authorities failed to provide sufficient protection when the risks of concussion and sub-concussive injuries were "known and foreseeable".

Marler’s cheeky selection features four All Blacks legends in his pack, with two each from Ireland and Wales.