Arnie's extra-time message to Westfield FFA Cup Final winners

Sydney FC boss Graham Arnold has revealed the psychological advantage his players gained prior to Bobo's extra-time winner in the Westfield FFA Cup Final on Tuesday night.

Level at 1-1 after a tense 90 minutes, a tiring Sydney came up with the decisive second goal in the 111th minute to see off Adelaide United.

The Sky Blues were coming off 48 hours less recovery than the Reds, but Arnold's simple message helped gain the upper hand.

"I said 'don't show them you're tired if you are'," Arnold told Fox Sports.

"It was about showing [Adelaide] we're fit, we're strong. We looked at them and they were on the ground. It gave us a bit of energy.

"It shows the mateship and the camaraderie in this group that they fight for each other and believe in everything we do. It was an outstanding effort."

Sydney's triumph was the club's first in the Westfield FFA Cup and capped an incredible third trophy of a record-breaking 2017.

However, Arnold is not about to give up the chase for further silverware.

"For me, that's the first of three trophies [for the 2017/18 season]," he said.

"Our motivation and our drive is the second one and that's the premiership.

"We'll find a date when we can celebrate this victory but for now it's about being professional and putting in a great performance against Brisbane [this weekend]."