The 18-year-old central defender for the Newcastle Jets admits he was stunned when SBS football analyst Craig Foster nominated him as one of the 10 best players in the competition this season.
Foster, in his column in last Sunday's The Sun-Herald newspaper, included Chapman in a list alongside stars Alessandro Del Piero and Shinji Ono, excitement machine Marco Rojas and leading goalscorer Daniel McBreen.
Chapman said he didn't immediately see the article himself, but was quickly alerted to it by his family.
"My mum sent me a link to the story, and then I read it," Chapman said. "At first I was quite shocked, but then I was very happy about it. Craig Foster is a big name in football, an ex-Socceroo, so it's definitely a great privilege to be rated in the top 10 by him."
Foster said Chapman had been "magnificent" for the Jets, adding that, in his opinion, "we are watching a future Australian captain mature before our eyes". It was extraordinarily high praise for someone so young.
Chapman, though, is determined not to be distracted, and says he has Newcastle coach Gary van Egmond to thank for helping to keep his feet on the ground.
"I'm not going to get carried away," Chapman said. "I've got a lot more hard work, and a lot more development, ahead of me.
"Gary pulled me aside after the article appeared and said: 'It's obviously a privilege to be rated as highly as that, but don't stop working hard'. That's his role in a situation like that, and I appreciate him guiding me.
"I'm only young, and I haven't reached my best in the A-League. I'm just starting to develop, so I've got a lot of learning ahead of me."
Asked how he was handling playing in a pressure position, and directing much older and more experienced players around, Chapman said it was a learning process that he was enjoying.
"It is a tough position, but every position has different pressures," he said. "You have to keep getting smarter all the time – that's what I'm learning in the A-League.
"You have to make sure your teammates are confident in you.
"When I first came into the team it was a bit daunting. You have to gain the respect of the other players by how well you play.
"If they respect you as a footballer, they will listen to you, and you are able to tell them where to go on the field, and what to do."
Like any promising young player, Chapman has his goals. He has represented Australia at age levels, and obviously wants to do it at senior level. He would like to play overseas eventually, but is in no hurry to make the move.
"I'd like to play in the A-League for another two years," Chapman said. "Maybe more, before I'm at that level. I have to prove to myself that I'm good enough in the A-League first."
It doesn't get any tougher than an away game against Western Sydney Wanderers at the moment, and that is what the Jets face at Parramatta Stadium on Saturday.
But Chapman says the fifth-placed Jets, based on their own recent form, are entitled to be optimistic about the clash with their third-placed opponents.
"The Wanderers are probably the number one team on current form," he said.
"Everyone in their team is doing well. But we're unbeaten in our last five games. We're working hard at training and fighting hard in games, and we're looking forward to playing them."