Sydney FC's chief executive Edwin Lugt has suddenly resigned, causing shockwaves through the club as they prepare to start their Asian Champions League campaign.

The club's new owner David Traktovenko enlisted Lugt just 18 months ago, but it is believed Lugt was not happy with Traktovenko's son-in-law Scott Barlow's increasing involvement.

Sydney FC are going through some turbulent times, having lost a number of other officials in the last week, and with their squad still to be finalised for next week's home game against Korea's Suwon Bluewings.