Patrick Kisnorbo says he knew it would take time for Mathew Leckie to readjust to the A-League Men as he backed the Melbourne City striker to keep on improving.

Leckie scored a 91st-minute winner in Saturday's 2-1 success over Sydney FC to send City to the top of the table.

After returning from a 12-year spell overseas, Leckie failed to find the net in his first five games back in the A-League.

The 31-year-old now has five goals in his last six matches and Kisnorbo said it was always going to be a slow process for the Socceroos forward to acclimatise to football in Australia.

"I think what we get wrong here is just because someone has a name they think it's just going to happen," Kisnorbo said.

"He's human and he's had to come home, learn to play a way which has been foreign for him for 12 years.

"He has adapted and keeps continuing to train hard and work hard. There's still a long way to go for him but I'm happy for where he is now.

"It's been a work in progress and he needs to continue that. I don't just look at the goals but a lot of things; positioning, first touch, runs behind."

Kisnorbo opted to bench young forward Marco Tilio for Saturday night's win which was City's third on the spin.

The 20-year-old, who had an assist and a goal in his two games prior to Saturday, played out the last half an hour, but Kisnorbo said he wanted to be mindful of balancing the youngster's workload.

"I think he needed some rest and he's played a lot of games recently," Kisnorbo said.

"My role is to pick the team but also to think of the player's welfare. I thought it was best for him to start on the bench and come on and make an impact.

"David Beckham and Cristiano Ronaldo didn't start every game. It's part of the journey for every young player, is he good enough? Yes.

"I showed that when we brought him in that he would get gametime. He has proven thus far he can play but we also know we need to look after players like that."