The Polish international put in a dazzling performance that set tongues wagging, displaying an exceptional range of passing and control which culminated in a standing ovation when he was substituted towards the end of the match.
While Mierzejewski’s resume initially triggered curiosity more than excitement – his career has been split between Poland, Turkey and the UAE – there is no doubt about his raw talent.
For Bobo, it’s just a relief to be on the same side for a change.
"I know all about him because I used to play against him when I was at Kayserispor and here was at Trabzonspor. He is a wonderful player and he’s coming to help us," Bobo said.
"You can see what he can he do and [against City] he was very special. He has a lot of skill and great touch and it’s great that he is here."
The Brazilian striker said the prospect of Milos Ninkovic and Mierzejewski linking up as attacking midfielders is a frightful prospect for rival defences, especially if himself and fellow striker Alex Brosque can get on the end of the opportunities the duo will create.
"Both Adrian and "Ninko" will become such important players for us [strikers], because a number nine needs those kind of players in behind," he said.
"We’ll need a bit of time to work everything out. Adrian is a great player but he’s new and sometimes it can be difficult to work out all the small details. But when we figure everything out, I’m sure we'll be even better."
The Sky Blues took an early lead thanks to a Jordy Buijs free-kick before a delightful lob from Brosque secured the win.
However, it was the on-field cohesion between the defence, midfield and attack over the 90 minutes that was the biggest positive.
"That’s exactly what we’ve been working on in training," Bobo said.
"We’re always talking about the need to have our tactics right, to move into the right places, to play that one-touch football.
"As a group, myself, Adrian, Ninko and Brosquey all focused on that style of quick passing and movement in training this week and it was pleasing to play like we did."
While Sydney were so impressive in the A-League last season, as they claimed their third championship, they fell in the final of the FFA Cup last year against City – but are now closing in on the one piece of domestic silverware that still eludes them.
"There’s two games to go now and given we played in the final last year in Melbourne, this year we need to win. It’s important for us. We’re a team that wants to everything we play in," Bobo said.
"Of course, we’re preparing for the A-League, but we talk about the FFA Cup and what we can do there. Every competition is important for us.
"Right now, we have the FFA Cup, the Asian Champions League and the A-League, and we want to win all of them. We have a great team and for us, we need to keep working to get better and better and to winning. That’s all we want at Sydney FC."
Bobo’s first season for the Sky Blues yielded 15 goals, just one shy of the club record set by Marc Janko in 2014-15.
In his second spell, he’s feeling good about reaching the heights that saw him finish the year as one of the league’s most feared poachers.
"I have no doubt that I can do it again and be even better this year. I feel good now, I’m just not yet at 100 per cent," he said.
"Now it’s about preparation, getting fit and when the league starts, I know I will be ready to go. We’re still in pre-season but with another three or four weeks, absolutely [I'll be at] 100 per cent. I’ve had one year here, but now I know this club, this league and I know what I can do."
