Latrell Mitchell will have just 80 minutes to work his way into the NSW squad with South Sydney coach Jason Demetriou claiming the fullback was too good to be left out of Brad Fittler's side for State of Origin III.

Mitchell will make his first start for Souths since round five when they take on Parramatta at Accor Stadium.

The fullback has been sidelined with a hamstring injury and was sent to the US to undertake a rehabilitation programme last month.

The 25-year-old returned to Australia a fortnight ago but his comeback game was delayed after he caught COVID-19, leaving Saturday night's game against the Eels as his only audition for Origin III in Brisbane on July 13.

Centres Matt Burton or Stephen Crichton loom as the most likely casualties if Fittler opts to recall Mitchell for game three at Suncorp Stadium, a ground where the Blues haven't won a decider since 2005.

"He's fit to play and he'll go out there and show what he's able to do and then it'll be up to NSW selectors and 'Freddy' (Fittler) to decide whether they want him in the team," Demetriou said.

"From our perspective, he is fit to play. I'd pick him, yeah, he's too good a player (to not be called up).

"But (as Souths coach) I won't be disappointed if they don't. If it was me, I'd be picking him for sure."

Souths (7-7) have yet to rekindle the form which earned them a spot in last year's grand final, with rookie halfback Lachlan Ilias and five-eighth Cody Walker struggling to combine.

Ilias, who was subbed off in their last game against St George Illawarra, will be one of the main beneficiaries of having the experienced hand of Mitchell alongside him.

"I don't want him (Mitchell) going out there expecting to be the bloke who's going to turn everything around," Demetriou said.

"He's got to do his job and he knows his role. He gives energy to the team and his presence alone will do enough."