City will kick off with a huge game against Sydney FC at Allianz Stadium next Saturday night.
Paartalu knows as well as anyone what sorts of players it takes for a club to be successful. He is one of those himself, having had a major influence on Brisbane Roar's success while he was at the club.
And Paartalu told The World Game that what the rest of us are seeing from Mooy in games, the City players are seeing every day at training as well.
Mooy, who was City's leading goal-scorer last season, with seven, scored a hat-trick in the team's 5-0 FFA Cup quarter-final win over Heidelberg United on Tuesday night.
He has now scored six goals in three games in that competition this season.
But that is just one part of Mooy's game. His playmaking and creating of goal-scoring chances has been outstanding, and he has cemented his place in the Socceroos squad.
"Aaron has reached a stage in his career where he definitely feels comfortable in his surroundings," Paartalu said.
"You can tell that from the way he plays. He's in, I guess, what they call the zone and he's very unpredictable.
"You try to mark him at training and it's very difficult to get close to him, so he's certainly going to be a big player for us this season. But we're all looking at ways to help him out because you can't have one man trying to win you the league.
"You've all got to pitch in and Aaron has probably taken a lot more of the load than he should, but while he's in this form I don't think many people can stop him."
Paartalu said Mooy isn't given enough credit for his football brain, and that it is the key to the midfielder finding space in a crowded engine room, when others around him cannot.
"I think they just think he's got good ball skills or he's good technically, but I just think he's very intelligent with his movement," Paartalu said.
"It's not 100 miles an hour, but it's always thinking about where the next pass is going to be and when he gets the ball he's so comfortable on it that he rarely makes mistakes and he opens things up for us.
"It's nice to play alongside him, certainly in my position because it makes my job a hell of a lot easier having that outlet to play the ball to someone like him."
Paartalu, operating in that holding midfielder role, said he was much better prepared himself for this season than last season, when he only joined City close to the start of the competition after playing his previous season in Thailand.
"It's a really big difference for me this year," he said.
"I came to the club three weeks before the start of last season and struggled a bit physically early on, getting up to pace and match fitness.
"But this year I've had 13 or 14 weeks of solid training with the team and I feel the best I've ever felt physically, in my whole career. Hopefully that's a good starting point for me this season."
City has gone deep into the FFA Cup despite having a lot of players out injured during the pre-season. Paartalu said most of those players were back in full training now and would gradually be seen as the club's A-League campaign takes off. Many of those players are attackers.
Paartalu said that if City had forwards scoring regularly this season it would probably be the key to the side going to the next level, after Mooy led the goal-scoring last season from the midfield. City has the potential up front, when everyone is fit.
City finished fifth last season, after Perth Glory was banned from the finals and dropped to seventh for cheating the salary cap, and beat Wellington in the first week of the finals before losing to Melbourne Victory in a grand final qualifier.
"We're certainly looking to make a bigger mark in the league this season," Paartalu said.
"We finished fifth and that's not good enough for a club that is as ambitious as ours and I think it comes down to consistency, which we didn't have last season.
"If you really want to be a serious contender, you've got to have consistency in everything you do. I think we're much more settled going into this season and hopefully that shows in consistency on the park."
