Shocked
But the Maroons mentor hopes the closure provided by Parker's surprise call to walk away at season's end ensures the backrower plays his best football for Queensland this year.
An emotional Parker stunned his Queensland teammates at their Gold Coast camp on Sunday night when he announced he would hang up the boots at the end of the NRL season.
It ensures Wednesday's Origin II clash will be his last in a Queensland jersey at Suncorp Stadium.
Asked if he believed 34-year-old Parker could have kept playing Origin, Walters said: "Yeah, I think most people would agree with that but obviously Corey has a different opinion.
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"But he knows his body more than anyone else.
"Good luck to him. We look forward to seeing him at his best on Wednesday night."
Parker has been rugby league's Benjamin Button, getting better with age for NRL club Brisbane and since resuming his Origin career in 2011 after a six year hiatus.
Walters did not expect that trend to end now that Parker had the peace of mind of drawing the curtain on his career on his terms.
"It's important for Corey now he has made his decision that he can get on with life and the rest of the season - hopefully he puts in another good performance," Walters said.
However, Walters did not believe sending out Parker an Origin winner would be a motivating factor for Queensland on Wednesday.
He said they already had enough motivation to seal a 10th series win in 11 years in game two.
"I don't think it needs that. I think playing in front of these passionate Queenslanders is enough (motivation)," he said ahead of Parker's 18th Origin.
"It (retirement announcement) hasn't been disruptive.
"They have got on with preparing for the biggest game of their careers."
The Maroons are favourites to clinch the series in game two despite a disruptive preparation.
Six players were struck down by a stomach bug at their Gold Coast camp while winger Dane Gagai missed the first week of training as he recovered from a quad strain.
Walters admitted it had been testing ahead of just his second Origin game at the Queensland helm.
"It has been one of those Origin weeks where lots has gone on," he said.
"But our focus has been really good, we have a clean bill of health.
The last time NSW kept a series alive by winning game two in Brisbane was back in 1998.
