Having filled in for wicketkeepers who suffered mid-match head knocks on three separate occasions this summer, Australia's T20 captain Aaron Finch has joined the chorus calling for concussion substitutes to be introduced in first-class cricket.

Finch particularly wants specialist substitutions, such as when a team loses its wicketkeeper to a "freak accident", to be allowed.

The powerful batsman twice stood in for Peter Nevill in Melbourne Renegades games during this summer's KFC Big Bash League, and performed the task again last weekend when Sam Harper suffered a head knock in Victoria's Sheffield Shield match against South Australia.

Harper struck by bat in Sheffield Shield

Nevill was first hit by an outfield throw that skipped off the edge of the SCG wicket, and was later in the season struck by a bat after it had slipped from Brad Hodge's hands. Harper was knocked down by the bat of South Australia's Jake Lehmann after the wicketkeeper was accidentally collected by the batsman's follow-through.

Finch said while the incidents involving bats were freak incidents, the specialised skills required to be a first-class wicketkeeper put a fill-in player in more peril.

Nevill struck in face by bat in BBL

"I know the Victorian players think very strongly that particularly a wicketkeeper should be allowed to be subbed out for another specialist wicketkeeper," Finch told reporters in Melbourne on Wednesday.

"It's a very dangerous position and is a specialist position at the end of the day.

"If someone's in there who's not qualified or doesn't have the right tools to do the job, then it becomes even more dangerous.

"It's easy for us (Victoria) to say because we've been on the receiving end of it, but there has to be some allowance for that.

"There has to be some way that you can sub in – whether they don't bat, that's a different argument – a specialist wicketkeeper.

"Where you've got someone who's technically and physically qualified to do that job."

Quick Single: Harper still in hospital following head knock

Cricket Australia Head of Cricket Operations Sean Cary confirmed on Tuesday that the Bushrangers would have been docked competition points had South Australia granted their request for a substitute for Harper, and the match may have lost its first-class status.

Following recommendations made in the Curtain Report – the independent investigation commissioned by CA following the tragic death of Phillip Hughes – concussion substitutes were introduced for domestic one-day and Twenty20 matches this summer.

Test opener Matt Renshaw was ruled out of the Sydney Test after copping a knock while fielding, prompting Bupa Support Staff team doctor Dr Peter Brukner to again call for the ICC to act.

Brukner explains the Renshaw decision

"The more examples we have of this, the more common it is, the more pressure there will be on the ICC to do something about a concussion sub," Dr Brukner said at the time.

"The concern we have is there's a tendency for the player and coaches and so on to want to continue, because they don't want to let the team down.

"It would be helpful in that regard if we had a sub, it would make it easier to pull players out with a concussion. But that's for the ICC and the politicians to sort out.

"We introduced it in the non-first-class cricket in Australia and it seemed to be successful.

"I think it's something that certainly needs to be looked at very seriously by the ICC."

Quick Single: Plenty on the line in Sri Lanka series

Meanwhile, the Australian Medial Association is set to take up the cause and lobby for the World Medical Association to take up the cause with the ICC.

Finch's team play the first game of a three-match KFC T20 INTL series against Sri Lanka at the MCG on Friday, while Australia's leading Test players will be involved in a practice match in Mumbai, and the captain said it would be difficult to build sustained success in the shortest format while it remained at the bottom of the pecking order.

Plenty at stake in Sri Lanka series: Finch

"I'd say out of the three (formats), T20 internationals would probably be the least prioritised until a World Cup year," Finch said.

"I understand that but it also makes it difficult. You don't play a real lot. I suppose it's a fine line ... how many (are) enough preparation to go into a world tournament and expect to be successful.

"I think if you're tacking on one or two games to the end of each series, the summers just blow out and become too long in my opinion.

"At the end of the day you have to rest people and you have to give guys a chance to be at their best for Test cricket and one-day cricket."