The Berries take on the reigning A-League champions in Tuesday night’s Round of 16 clash at Edensor Park.
Although the Sky Blues demolished minnows Darwin Rovers 8-0 during the previous round, Moustakas is confident his side has can claim a shock victory against the A-League powerhouse.
“The hardest game is when you have to go into the unknown,” Moustakas said.
“Sydney FC’s record from the past 12 months has been incredible, but if they underestimate us football can be funny.
“They will come in determined to get a job done but we are very motivated for this match and are going to make it as hard as possible for them."
Moustakas, 34, an 11-year veteran of the Cypriot league and a former NSL player, has experienced the highs and lows of a professional playing career featuring league titles, domestic cup wins and even a taste of UEFA Champions League football.
While he hasn’t completely put an end to his playing days just yet, the former Cyprus Under-21 representative has made the move into coaching and is hoping to guide his Berries team to an historic victory.
“The keys to a match like this are character, belief and teamwork,” Moustakas said.
“If Sydney FC’s players run 10km in the match we are going to run 12km. Team spirit and determination are areas where I think we can have the upper hand against Sydney.
“Football can be a funny sport and anything can happen during the 90 minutes. We are certainly going to take the game to them as much as we can.”
While the attention will be on the players who take the pitch against their A-League counterparts, the Berries' gaffer said the FFA Cup is just as much a chance to recognise the unsung heroes of the community club.
“The most important thing for me is I hope for those who work so hard at the club that we can put a smile on their face and give them something they can remember fondly,” Moustakas said.
“There has been plenty of excitement around the club leading into this match and all of the players are motivated to give a performance the club would be proud of.
“Hopefully we can get a strong crowd to support us on the night and just maybe we can come away with a memorable result for them.”