One day before facing former club Melbourne Victory, Danny Vukovic has been laid up at home popping vitamins.
The Sydney FC goalkeeper sat out Friday's final training session with a virus that's already worked its way through teammates Michael Zullo, David Carney and Milos Ninkovic.
His recovery is a priority ahead of Saturday's blockbuster Big Blue at Allianz Stadium because coach Graham Arnold needs Vukovic's safe hands against a staunch rival they haven't beaten in nine meetings.
On an individual level the match shapes as Vukovic's sternest test yet, against the team he played for last season.
And the gloveman is adamant nothing will stop him taking his place between the posts.
"I'll play with a broken leg if I have to," Vukovic said.
"We just thought better to rest until Saturday night rather than exerting myself a little bit and slowing the healing process down.
"I'll be a lot better in 24 hours, and the adrenaline will get me through."
He'd want to hope so, because he could be busy.
Vukovic is braced for the menace that is Besart Berisha, the ex-teammate who netted a hat trick in Monday's 6-1 shellacking of the Wellington Phoenix.
On a larger scale, he knows from experience how formidable Muscat's Victory can be, particularly when pumped up on a big win.
"They showed [against the Phoenix] just how dangerous they can be when they get it right," Vukovic said.
"They were showing signs of a game like that and maybe been a little bit unlucky at the start of the season.
"But they're always capable of a result like that with the attacking players they've got.
"It's really important we turn up ready to play and nullify their opportunities in front of goal.
"If we keep a clean sheet there's a very good chance we'll win because we've got some very good players in our front third who are putting the ball in the back of the net regularly."
Clean sheets are Vukovic's specialty.
The 31-year-old has rediscovered form and is the only custodian in the league with a perfect four clean sheets.
He also ranks second for saves with 12, just one fewer than Lawrence Thomas, the man who displaced him amid a late-season form slump at Victory.
Vukovic insists there'll be no strange emotions during the game.
"I've played for quite a few clubs in the league and had to do it before," he said.
"I played with them last season, that's in the past now and I'm focusing on what I need to do for Sydney FC."