Peter Handscomb has been confirmed as a replacement for Marsh for the remainder of the tournament, the International Cricket Council (ICC) said.
“Shaun Marsh has had scans on his right forearm after being struck while practising in the nets at training today,” said Australia head coach Justin Langer. “Unfortunately, the scans have revealed Shaun has suffered a fracture to his forearm which will require surgery.”
“This is obviously shattering news for Shaun and the squad. Throughout this tournament, his spirit, professionalism and the way he has competed has been typically outstanding,” he added.
All-rounder Glenn Maxwell was also struck on the right forearm by a Mitchell Starc delivery during the net session, but escaped serious injury, the Australian Coach said.
"The scans have cleared Glenn of any serious damage and we'll continue to monitor him over the coming days. We are hopeful he will be fit to perform for us on Saturday against South Africa," Langer said.
“We have made the decision to call up Peter Handscomb to replace Shaun in our World Cup Squad of fifteen,” he added. “Pete is a like for like player, in terms of batting in the middle order, and he performed very well for us during our recent tours in India and the UAE.”
The replacement of a player requires the approval of the Event Technical Committee before he could be officially added to the squad.