John Millman insists he won't hesitate in fighting through illness all the way to a possible Sydney International final, even if it it hampers his Australian Open preparations.
Millman became the third Australian male through to the quarter-finals of the grand slam warm-up event after defeating Marton Fucsovics 6-3 6-4 on Wednesday night.
For the first time in five attempts in the harbour city, Millman joins countrymen Alex de Minaur and Jordan Thompson, who meet for a spot in the semi-finals, in the final eight.
First he'll have to overcome fourth-seeded veteran and former Sydney champion Gilles Simon, who toppled American Sam Querrey in three sets on day four.
After featuring in the Fast4 exhibition alongside Nick Kyrgios on Monday, the 38th-ranked Millman almost withdrew before staging an epic three-set win over Frances Tiafoe on Tuesday.
Last year's US Open quarter-finalist has now played over six hours of tennis in three days but is willing to push his body to the limit before heading to Melbourne Park.
"ATP tournaments, week in and week out, they are tough things. I'm now in a position where there is only eight more people left, and one of us has to win it," Millman said.
"It's not in me to ... I'm really kind of thinking kind of one tournament at a time.
"Playing this week, always the idea is to try to go as deep as possible, try to create as many opportunities as possible. And we'll tackle Australian Open when it comes."
Millman was in control from the outset on Ken Rosewall Arena, winning five of the opening six games and keeping the Hungarian world No.35 at arm's distance the rest of the way.
The Australian No.2 admitted he is still feeling under the weather.
"I'm not 100 yet, but we're getting there. Hopefully over the next few days I continue to recover. I was speaking to the doctor then and been looked after really well here," he said.
"I'm just happy that I'm playing through this, and hopefully then when you start feeling a little bit better, the game kind of goes to the next level."