Sydney FC chief executive Tony Pignata has implored the club's fans to come out in full force for Wednesday's Asian Champions League round of 16 second leg against Shandong Luneng, claiming it ranks as one of the most important matches in the club's history.

While many thought victory to the Western Sydney Wanderers in 2014 would accelerate national interest in the competition, promoting the tournament to Australian fans remains a particularly tough sell in comparison with the A-League.

Sydney FC began their home ACL campaign against Guangzhou Evergrande with a crowd of 18,149 – but almost half came in support of the visiting team. The next match, against Korean side Pohang Steelers, saw only 5642 attend and despite Urawa Reds' reputation as an Asian superpower, just 8802 turned up.

Shandong Luneng have a smaller footprint in Australia and while they are expected to bring some support to Allianz Stadium, it won't be enough to swell a crowd that Pignata feels won't match the significance of the occasion.