Sydney FC have been shocked by the resignation of CEO Edwin Lugt on the eve of the Asian Champions League.

Just under a year ago, Lugt was reveling in the Sky Blues' Premiership/Championship double but now he has decided to end his tenure with the club as they prepare for the ACL which kicks off next week.

The move comes as a surprise as Sydney had just made a couple of key player signings for the Asian competition and Lugt had only been in the job for 18 months.

Sydney are expected to officially announce the Dutchman's decision soon and indicate to supporters what they next plan to do.