The injury throws Australia's plans into disarray with only weeks to go for the World Cup in India, starting on October 5.
Fingers crossed with the World Cup fast approaching,' McDonald added. 'I'm not a medical person but I think it's a bit higher up than the finger itself. 'He's going to go in for more scans tomorrow to get a detail of that, then we'll work out the management of it from there. 'As to the nature of what sort of time frame that lends itself to, that will be assessed tomorrow,' he added More scans on Saturday will reveal the extent of the injury.
'It's a confirmed fracture,' Australia head coach Andrew McDonald said at the post match conference.