St Kilda champion Nick Riewoldt says a worrying pattern has emerged in Christian Petracca’s game since his life-threatening injury last year.

Petracca famously suffered horrific damage to his spleen during the King’s Birthday clash against Collingwood last year, which saw him taken to hospital and later transferred to ICU.

WATCH THE VIDEO ABOVE: Christian Petracca dealing with ‘mental demons’ after spleen injury.

He missed the rest of the year as football became a secondary priority in his battle just to regain health.

On return this season, Petracca has averaged 25.3 disposals and nearly a goal a game.

But Riewoldt, who last week was inducted into the Australian football Hall of Fame, says Petracca is backing out of contests — particularly aerial ones — and avoiding contact like he never used to.

“One of the big issues they’ve (Melbourne) got centres around Christian Petracca, and there’s a real human element to this as well,” Riewoldt said on Monday night’s episode of The Agenda Setters.

“He suffered the massive injury last year (on) King’s Birthday where he opened himself up, we know it.

“And I’ve just been watching him — he’s a watch, Christian. Because I think the mental demons in his head, they’re rearing their head way too often.”

Riewoldt showed a number of clips from this year — one of which came from Sunday’s loss to Port Adelaide — where Petracca appears to shirk contact.

“Again, that’s a situation, pre-injury, he’s going back harder than that,” the Saints champion said as the vision played.

“It wasn’t a one-off either; we’ve seen it all year when he has to open himself up, he just doesn’t have the same intensity at the football.

“And I think it’s understandable. The fear or the threat of getting hit in the same spot, I think, has become a really big thing for him.”

Port Adelaide premiership player Kane Cornes said it posed a vexing question for Demons coach Simon Goodwin.

“It’s a really strong pickup, and we are all understanding of this and what he’s going through in his mind in that moment,” Cornes said.

“It’s been about love and it’s been about protection, it’s getting him back, falling in love with the place, bringing his family back after the damage that was done.

“How do you possibly coach that out of his game?”

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Goodwin was asked about it after Sunday’s game, but hosed down suggestions Petracca is still finding his feet post-injury.

“Trac’s right back to his best, he’ll go to every contest the way he normally would,” Goodwin said.

“He wants to be an aerial player, he wants to be a ground-ball player, but that’s (the injury) well in the past and we’ve moved forward, and Christian’s spent a lot of time working on that stuff, so he’s fine.”

But Riewoldt disagrees, and says it’s something he needs to train, to get his confidence back.

“He is dealing with something that none of us dealt with as a player, that life-threatening injury, so I understand that there would be a trepidation around those sort of contests,” he said.

“But as a leader of a football club, I think you’ve just got to train it and put yourself in the position — almost get comfortable getting your arms up and taking contact again.

“Because at the moment, it looks like he’s unsure about his own body in that contested situation.”