Flanagan predicts 'something special' on Anzac Day

St George Illawarra coach Shane Flanagan is expecting the unexpected as his side aim to stage an upset over the Sydney Roosters on Anzac Day.

The 23rd edition of the Anzac Day Cup will be contested before a sold-out Allianz Stadium on Thursday, with Flanagan making his first appearance in the fixture as a head coach.

But the 58-year-old is no stranger to the traditional clash, having served as an assistant to then-Roosters boss Ricky Stuart between 2004 and 2006.

In the first of Flanagan's three previous Anzac Day appearances, Brad Fittler scored a memorable 50-metre individual try, stepping around Ben Hornby and seizing control of the game for the Roosters.

Easts would go on to win the clash 11-8, with victory sealed by a Brett Finch field goal.

A year later, Flanagan watched on as Dragons halfback Mathew Head kicked a sideline conversion to sink the Roosters 26-24 in a match sometimes credited as the best played on Anzac Day.

The fixture also has a knack for being close, seven of the past nine having been decided by 10 points or fewer.

Reflecting on his time at the Roosters, Flanagan expected plenty of intrigue come Thursday afternoon.

"What I learned from those games was that it is something different," he said.

"It's a little bit like Origin in that there's always something special happening.

"There's always something special in these games. Hopefully it's our way tomorrow."

Roosters coach Trent Robinson says the traditional clash is as an opportunity for James Tedesco to prove his doubters wrong amid debate over the club's fullback spot.

Tedesco had a tough night in last week's loss to Melbourne, coming under fire for tripping Ryan Papenhuyzen and finding himself burnt by Jahrome Hughes for the Storm's first try.

Joey Manu, meanwhile, is in brilliant individual form despite the Roosters' indifferent start to the season.

The New Zealand international was particularly strong switching from the centres to replace the concussed Tedesco in the round-six win over Newcastle.

With the Roosters looking for consistency, Gorden Tallis has been among those to suggest rugby union-bound Manu could spark Robinson's side as a full-time fullback.

But Robinson defended Tedesco, whom he called "the form player for the first month of the season".

"If anybody looks at the way the games were played, I think that was pretty clear," Robinson said.

"He copped a head knock and missed a game and came back and was below what he wanted. I think one game was not what he wanted, but before that he was in really good form.

"That's my view and he'll keep being our captain and fullback. Let's prove them (the doubters) wrong."