FourFourTwo understands Franjic, 28, lost several kilograms during a mystery illness which has left him close to a month behind in his pre-season programme.

Franjic hasn’t been sighted in City’s pre-season wins over Melbourne Knights and Port Melbourne.

He also missed this week’s 2-1 FFA Cup win at Floreat Athena in Perth.

City coach John van ‘t Schip fielded a close to full-strength line-up against Floreat with only Neil Kilkenny (foot), Corey Gameiro (anterior cruciate ligament) and Franjic absent.

The 2014 World Cup Socceroo had been looking fit in pre-season, having missed the 2015-16 finals due to a hamstring issue.

Franjic’s setback has seen his weight and conditioning deteriorate significantly. His availability for Round One will depend on his ability to recover upon his return to training.

FourFourTwo understands Kilkenny’s foot injury is only minor while ex-Sydney FC striker Gameiro is currently on track to be fit for Round One.

Gameiro will not be rushed, though, as City’s medical staff are taking a precautious approach after successive long-term ACL injuries.

City begins its A-League campaign on Saturday 8 October away to Wellington Phoenix.