For Green Gully forward Nicholas Krousoratis, much of 2016 has been a write-off as he has struggled for fitness and game time because of the condition.

But he shrugged off his ailment in tremendous fashion to be the difference player for Gully in its 3-1 win over Melbourne Knights, which takes them into the last eight of the FFA Cup for the first time and consolidates their giant-killing performance in the previous round, when they knocked out A-League strugglers Central Coast Mariners.

Krousoratis was a thorn in the Knights' side, scoring once and offering a threat in attack throughout the game.

But coach Arthur Papas revealed post-match that the 22-year-old had been in doubt as a starter until the day of the game.

It was only a series of text messages between Papas' assistant, Shaun Ontong, and Krousoratis that persuaded the youngster that not only could he be involved for the first time in three months, but that he could also start a match in which he was destined to play a key role.

"With some nice persuasive messages to Nick, he agreed to start and he hasn't started a game for over three months and gave us a completely different element in the way we attacked," Papas said.

"He has improved from when we played them in round 14 [of the NPL Victoria competition]. It was the first game we left him out completely because of his osteitis. We felt that we could nurse him and give him 20 to 30 minutes for these sorts of games.

"He put his body on the line ... he is an exceptional talent for his age," Papas said.