He's been slugged with the lazy tag in the past, but in-form Perth Glory striker Nicholas D'Agostino says he's now as fit as he's ever been and eager to continue his hot start to the A-League season.

Then-Glory coach Tony Popovic gave D'Agostino a public roasting last season after the Olyroos striker returned from the COVID-19 shutdown in inadequate shape.

"He needs to know if he wants to be the best, he needs to present as the best, and he hasn't done it so far," Popovic said at the time.

New coach Richard Garcia has put a focus on helping D'Agostino understand his professional responsibilities, and the results to date have been stunning.

D'Agostino has scored four goals in five games to stamp his name as one of the league's in-form strikers, and he'll be aiming to continue his purple patch when he takes on his former side Brisbane Roar in Perth on Friday night.

The 22-year-old, who wants to be part of Australia's Olympic squad later this year, admits he has struggled in the past to maintain his fitness when away from the group.

"Some people call it lazy," D'Agostino said.

"But I don't know, I just like being around the boys and like getting out here and training, and just having that camaraderie, learning as much as we can together and getting that chemistry on and off the pitch.

"When we had that big COVID break ... that was three months off. It's not easy for a professional athlete to have three months off, and no real structure, and coming back and starting pre-season again twice in a season.

"It's tough, but I'm as fit as I probably ever have been at the moment."

D'Agostino now has a greater understanding of what he needs to do to stay fit during extended breaks, saying it's important not to give himself too much time to relax.

He also heaped praise on Garcia for allowing the playing squad to express themselves out on the field.

Garcia feels D'Agostino's growing maturity has played a key role in the striker's improved fitness.

"I think he's taking his football to a different level," Garcia said.

"He's maturing as a person, he's a wonderful player, and his confidence is sky-high, not only in football, but himself, which is fantastic to see."

Perth have only played five games this season - the most recent being a 2-1 win over Adelaide on February 5.

Glory players were forced to go into two weeks' quarantine upon returning to Perth, and they face a big challenge against a battle-hardened Brisbane outfit who have played four games in February alone.