Red Rob Earns First Start

Cornthwaite comes into the starting XI for the first time since heading in the equaliser in United's 3-2 loss to Jeonbuk Motors in the Round of 16 AFC Champions League clash at Hindmarsh Stadium in May this year.

Coolen has eased the towering defender back to match fitness, after missing most of the pre-season with a groin injury, bringing him on after the hour mark in the Reds' previous two matches.

The Dutchman knows all too well the attacking threat Cornthwaite poses in the air while remaining a frightening figure in defence.

"He's normally a fit player so I'm happy that he starts tomorrow. We'll see how it goes," Coolen said.

"Robbie has had full training the last two weeks and that's why I've given him 30 minutes in the last two games.

"We don't know if he can play 90 minutes, maybe, it will depend on how the game goes.

"He's a good header, he's strong, he's tall, probably tomorrow he won't be involved in every moment of the corners or free kicks because we have to be careful for him."

Coolen admitted he would have liked Cornthwaite to have had a full 90 minutes with the Baby Reds, but the National Youth League is set to kick off this weekend.

Fabian Barbiero will return to action with the youth league side as the classy midfielder returns to full match fitness.

"Normally I prefer with those kind of players to have more match practise when possible in the youth team, like Fabian," Coolen said.

"He's playing a game tonight, 45 minutes and I'm really happy for that.

"But normally if you bring a player back in your squad and you want him to play 90 minutes, I prefer he plays 90 minutes in the youth team or a friendly match and we haven't had the time for that.

"He's fit so there's no problem."

The Reds' boss conceded he has little choice but to throw the lanky stopper in from the start with Mullen on national team duty and Nigel Boogaard on the sidelines with a serious ankle injury.

Coolen admitted he is eagerly awaiting when United has a clean bill of health, adding competition for places in the squad will be hotly contested giving the Dutchman more options and choices to make.

"If Daniel was available maybe we could have started with him, because Daniel can also play at right back, he's done that very well. But, (Cameron) Watson is doing ok at the moment," he said.

"We would have had a choice (if Mullen was available) but there is no choice for me.

"I don't know what will happen in a couple of weeks when everybody is available but I'm really looking forward to that moment so that I can make choices because we need more competition."

Argentine playmaker Marcos Flores has recovered from a back complaint and will start, despite speculation to the contrary earlier in the week.

The South American star has been labelled the Reds lucky charm with United undefeated in seven league matches since Flores debut, ironically a 2-0 win against the Roar at Hindmarsh Stadium in the penultimate round last campaign.

Coolen admitted he has heard the 'lucky charm' theory but wasn't aware of the seven-game streak, also conceding every match without defeat means their first loss is closer.

"That's what I've heard, every week that game comes closer and closer, you will lose a game," he said.

"I didn't know that, I don't watch so much the stats. But it's a positive thing and (the lucky charm idea) is the reason I start with him tomorrow.

"Normally he can (last 90 minutes), but last week he didn't because he had some problems with his back. I was happy that he could start.

"We knew at the end of the game that maybe he would have some problems.

"But Marcos is a real talented player, he's an important player for us but he also has to do a lot of defensive work."