Demetriou has been taking instructions from quarantined head coach Wayne Bennett all week but will be handed the keys during the game against the struggling Cowboys at Queensland Country Bank Stadium on Saturday.

Sitting seventh and with little top-eight breathing room, it's a prime opportunity against a Cowboys side that's won just two of 11 since the season's resumption.

Demetriou said the undermanned Storm's clinical effort against the Roosters on Thursday night was the perfect example of how to get a result when it mattered most.

"The Storm showed us last night what happens when a group of men just commit to what their job is and go out and execute," he said.

The Cowboys were hammered 30-10 by Gold Coast last weekend, playmaker Michael Morgan having a return to forget with seven missed tackles and four errors.

It was his first game since March after shoulder surgery, while the Test and Queensland half had also welcomed his first child just days before the game.

Demetriou said his team would test him out again on Saturday if given the chance.

"They're not going to be solely targeting Morgs ... if there's an opportunity to do that sure, the boys will take it, but it won't be something we'll be focusing on," the former Cowboys assistant said.

"I thought after the birth of his baby and coming into his first game in six months was going to be really difficult to do.

"What I do know about Morgs is he won't do that again this week; he'll be up for a big game and he's a player that can do a lot of damage if given the opportunity."

A loss would be the Cowboys' first seven-game losing streak since 2008, although there was some positive news with interim coach Josh Hannay rating Valentine Holmes a chance to return next weekend.

Hannay said Morgan was keen to make last weekend a "distant memory" and ensure the trip from Sydney stung the Rabbitohs.

"We can make the trip seem long by how we play but (a sloppy start) will give life to South Sydney and they'll grow a leg," he said.

Set to assume the head coaching role from 2020, Demetriou doesn't see this two-week gig as an audition.

"I see myself more as a relief teacher at the moment ... it's my job to carry out those instructions (from Bennett)," he said.

"In 18 months it's about building a culture and team that represents who you are as a coach - it's pretty hard to do that in two weeks mid-season."

STATS THAT MATTER

* A Cowboys' loss would make it seven straight for the first time since 2008.

* The Cowboys have failed to score more than 16 points in a game during their current losing streak.

* The best linebreak combination in the league is Latrell Mitchell to Dane Gagai, Mitchell assisting seven of Gagai's linebreaks this season.

Australian Associated Press