Sydney - Australia urged the International Cricket Council to follow their lead and introduce concussion substitutes after opener Matthew Renshaw was ruled out of the third Test against Pakistan following a blow to the head.
The 20-year-old rookie was feeling unwell and suffering headaches after being hit on the helmet for the second time in three days during the Sydney Test.
Cricket Australia have new rules in place for concussion subs in domestic games following recommendations from an independent investigation into the death of Phillip Hughes, who died after being struck by a bouncer during a Sheffield Shield match in November 2014.
Team doctor Peter Brukner called on the ICC to consider similar rules for international matches.
"The more experience we have with this, the more common it is, there will be pressure on the ICC to do something about a concussion sub," Brukner told reporters in Sydney.
"The concern we have is there is a tendency for the player, and the coaches and so on, to want to continue, because they don't want to let the team down, they don't want to be a player short.
"So it would be helpful in that regard if we had a sub that would make it easier to pull players out with a concussion. That's for the ICC and the politicians to sort out really. I'm more concerned with looking after Matthew."
Brukner said he had not been pressured by the Australian team to allow Renshaw to play on in the Sydney Test despite his blows to the head.
"At this point I have to say the coach and the captain have been absolutely supportive," he said.
"They've said to me all along, 'It's your decision, doc'. I've had no pressure at all to keep Matthew in the game."
Renshaw was struck on the helmet while fielding close to the bat on Thursday. He was also caught by a bouncer while batting on Tuesday.
Brukner said Renshaw had complained of suffering headaches after the latest blow.
"He rested in the dressing room and then, when we returned to the hotel, we performed concussion tests and his cognitive, balance, coordination and reaction times were all within normal limits," he said.
"However, on Friday morning he was still symptomatic and so we have taken the decision to withdraw him from the match as he is suffering from concussion."
The Yorkshire-born player scored 184 in the first innings for a maiden century in his fourth Test.
Brukner said wicketkeeper Matthew Wade would play Friday after recovering from a stomach illness, which forced him from the field on Thursday.
Peter Handscomb took over wicketkeeping duties in Wade's absence.