The Young Socceroo was hospitalised in New Zealand with concussion and had to be left behind when the rest of the team flew home as he was unfit to fly.

But he is now set to return to first team contention for the club’s blockbuster inaugural derby against Western Sydney Wanderers on Saturday.

Antonis missed the Sky Blues 3-2 home loss to Newcastle on the weekend and club staff admit his decision to play on with the head injury was “pretty silly”.

The 18-year-old failed to mention a problem with coaching staff at the break and only brought the problem to light following his substitution in the second half.

“None of us saw it but looking back it happened in the first 20 minutes when he got a bit of a head clash and played on,” a club spokesman said.

“He didn’t tell anyone until he came off. And then when he came off, he was feeling a bit dizzy so he was taken to hospital.”

Head coach Ian Crook now has a headache of his own with the team’s porous defence suffering yet another blow.

Defender Adam Griffiths has been ruled out of the derby with a hamstring injury while influential centre-back Pascal Bosschaart is still some weeks from a return to first team action.

Bosschaart played 30 minutes in a youth team friendly against Central Coast last week more than six months after rrupturing his Achilles tendon in the Sky Blues final game of last season.

The uncompromising defender took to Twitter to encourage his team in the wake of Sydney’s disappointing home loss to the Jets in front of more than 35,000 fans.

“The day after a game (loss) is always hard even if you didn't play. I would say heads up and work towards the sydney derby,” Bosschaart tweeted.

And followed up with: “Believe me guys. Doing everything to get back. Most important is then to stay back.”

A round six return looks a realistic target for the Dutchman when Sydney FC take on bitter rivals Melbourne Victory at home for the first Big Blue of the season.