• Muscat and La Rocca collide with Sydney FC's Ninkovic during their FFA Cup fixture (Getty Images AsiaPac)
Sydney FC coach Graham Arnold says the Sky Blues' performance in their FFA Cup win over holders Melbourne City on Wednesday was nothing compared to the team's "scary" form in training.
Source:
AAP
14 Sep 2017 - 2:58 PM  UPDATED 14 Sep 2017 - 3:10 PM

The A-League champions barely got out of second gear against the big-spending City, in a rematch of last season's cup final, as goals from Jordy Buijs and Alex Brosque secured a spot in the semi-finals.

Aside from eyeing a maiden FFA Cup crown, Sydney FC are looking to become just the second club to win back-to-back A-League titles.

Arnold believes his side can improve dramatically.

"I have seen better than that at training easily, and some of our training sessions are quite scary," he said.

"It is a good start but we have a hell of a lot of improvement in us.

Sky Blues end cup reign of lacklustre City
Sydney FC earned a dose of revenge for last season's FFA Cup final defeat against Melbourne City with a one-sided 2-0 win to reach the semi-finals, while a Nikola Mileusnic hat-trick inspired Adelaide United to a 3-0 win over Heidelberg United.

"The whole left-hand side is new and when they get more settled with each other, the performance will get greater and greater.

"I'm happy to dominate Melbourne City so easily the way we did, but we could have been more clinical and scored more goals."

The only concern for Arnold post-match were injuries sustained by captain Brosque and left-back Michael Zullo.

The former limped off the field in the second half with what appeared to be a serious ankle injury but reports on Thursday suggest both players will return to action within a fortnight.

Sydney appear to have uncovered another high-quality import, with 40-cap Poland international attacker Adrian Mierzejewski impressing in his first start for the club.

"That (Mierzejewski's performance) is about 30 per cent to what I have seen on video," Arnold said.

"He is not fit and once he gets settled I believe he will be a very exciting player for Sydney FC."

Sydney FC now await Wednesday's FFA Cup semi-final draw with Western Sydney Wanderers and Adelaide United the only other A-League clubs still in contention.