'No doubt': Alex McKinnon's stunning call on Cameron Smith

Former NRL star Alex McKinnon has put to bed any doubts about his feelings towards Cam Smith, after making a stunning call about the retired legend.

Melbourne Storm, Queensland and Kangaroos legend Smith's sudden retirement last week took the rugby league world by surprise, with tributes soon flowing for a player described by many as the greatest they've witnessed.

'JUST AMAZED': Cowboys slammed over Jason Taumalolo tactics

'REAL SHAME': Birthday boy's horror injury shocks fans

COMING BACK?: Yvonne Sampson fuels stunning Cam Smith theory

McKinnon - despite once admitting to having a hatred of Smith - is one of many who that insist Smith is the rugby league GOAT (greatest of all time).

The pair have a chequered history after the 2014 incident that left McKinnon paralysed, wheelchair-bound and unable to play rugby league again.

Smith was heard arguing with the referee after the tackle that ultimately left McKinnon a quadriplegic - an incident that led to widespread condemnation of the Storm captain.

However, when discussing Smith's retirement from the game and the legacy he's left on rugby league, McKinnon proved that the controversy surrounding the NRL great is water under the bridge.

“I have no doubt and no hesitation in saying Cameron Smith is the greatest player I have seen and the greatest player to have played the game,” he told the Sydney Morning Herald.

“If I bumped into him I’d like to congratulate him on his career.”

McKinnon's comments may come as a shock considering the strong resentment towards Smith that used to consume him.

The 29-year-old - who announced in November that he and wife Teigan are expecting twins in May - last year lifted the lid on his feelings for Smith, following the controversial incident that left him paralysed.

McKinnon once 'consumed' by hate for Smith

Smith became an easy target for hate after he was heard arguing with referee Gerard Sutton about the incident, once McKinnon had been stretchered off the field.

No one at that time knew the extent of McKinnon's injury, with Smith explaining to Sutton that it was a terrible accident.

"It’s unfortunate and I don’t want see that happen any time in our game," he said.

"If he doesn’t duck his head, that doesn’t happen."

Smith copped a wave of backlash after the comments were aired on 60 Minutes.

McKinnon admitted that hatred towards the Melbourne skipper had consumed him for some time, but that he'd learnt to move on from the devastating incident and forgive Smith.

"I have no emotion when it comes to Cameron Smith these days," McKinnon told the Sydney Morning Herald.

"I have forgiven everything that happened straight after the tackle, his response – I have forgiven him. It’s hard to hold on to hate. It really is. It’s wasted energy. It’s blinding.

"At its worst, it can consume you and I’ll admit it did for a while there."

The former Knight - whop now works as the club's recruitment manager - said it was even harder for his father to forgive Smith, but he too has learnt to move on.

"The hard thing was for my family, my dad, to let it go," he said.

"My dad can now observe something that Smith has done and not see it in a negative light."

Click here to sign up to our newsletter for all the latest and breaking stories from Australia and around the world.