David Warner was left "pretty shaken" after a full-blooded drive hit a net bowler on the head, according to Australia captain Aaron Finch.
Australia were training at the Oval ahead of their World Cup encounter against India on Sunday when the incident happened.
The training session was immediately halted as the bowler was attended to straight away by medical staff on site at the London venue before being taken to hospital for checks.
Finch said: "Dave was obviously pretty shaken up. The young guy seems to be in pretty good spirits at the moment.
"He's obviously been taken off to hospital and will continue to be assessed just to make sure that everything is OK. But yeah, Dave was pretty shaken up, no doubt.
"It was a decent hit to the head. Hopefully everything keeps going well for the youngster and he's back up and running shortly. It was tough to watch."
As a precaution with any head injury, the necessary checks were made, with the man put on a stretcher and then taken away to hospital for further examination.
An ICC spokesman said the bowler was "responding well" and was "conscious when he left".
The ICC added in a statement: "The ICC can confirm there was an incident involving a net bowler during the Australian practice session at the Oval.
"The bowler was hit on the head in his follow-up. He was treated immediately by the medical staff at the ground and has been taken to hospital as a precautionary measure."
Cricket Australia confirmed that the bowler was being monitored for delayed signs of concussion, but a CT scan had cleared him of any major damage.
Warner took some time out from the session once training resumed, before returning to the nets.
In 2014 he was fielding in the Sheffield Shield match in which his friend Phillip Hughes was hit in the neck by a bouncer. Hughes died two days later.
Defending champions Australia have won both matches so far and Finch believes it is imperative for his pace attack to strike early in order to knock Indian batsmen Virat Kohli and Rohit Sharma out of their stride.
Finch said: "Once he [Kohli] getsĀ into a rhythm he's so hard to stop and you can't afford to play catch up against great players, and Rohit is the same.
"He's so destructive when he starts to really put the pressure on you. You can't afford to give them too much freedom, but we can't focus on just two players either, look at the rest of their batting line up.
"Those first 10 or 15 balls it's about making them take a risk and early wickets will be a real key."
But Sharma is in the mood to do more damage after a superb 122 helped his team cruise past South Africa in their opening match.
"I was happy with my performance against South Africa," said Sharma.
"I had to curb my natural instincts and play to the conditions and that gives me immense satisfaction. It wasn't my best innings but it was one of my best."