McCarthy was encouraged by the playmaker's first outing of the season in the 1-0 win over Maritzburg United in the MTN8 quarter-finals at Harry Gwala Stadium last weekend.
The 25-year-old, who scored six goals and provided five assists last term despite reports of ill-discipline, reiterated his ability in a 74-minute spell in Pietermaritzburg.
"Listen, he [Patosi] hasn't played the first two games and on Sunday he made himself stand out," McCarthy said.
"We wanted him playing between the lines in the first half and getting into those little pockets of space. He made us play, so that was good.
"It's going to take time. It's a process and you don't lose weight overnight you know. So I think he has done amazing and is a player that the team needs very, very much. And ja, he's a work in progress like I said.
"We are working hard with the fitness department, the physical guys, the fitness coaches. They're working hard to get Pato to get to his best because in my opinion he's probably the best player we have in South Africa in terms of quality."
City next host Golden Arrows in the league at Cape Town Stadium on Saturday (18h00).