Australia's World Cup hero Stephen Larkham has called on Super 12 referees to take a tougher stand against foul play after he was flattened in last weekend's opening round of the Southern Hemisphere tournament.

Larkham, whose extra-time drop goal against South Africa propelled the Wallabies into last year's World Cup final, said the sport's new regulations allowing referees to sin-bin players were not effective against more blatant rough-house tactics.

The ACT Brumbies flyhalf was floored three separate times during last Friday's loss to Auckland after being hit with head-high tackles after he'd kicked the ball.

South African referee Andre Watson, the same man who handled last year's World Cup final between Australia and France, sin-binned Doug Howlett, Justin Collins and Troy Flavell for their late tackles but Larkham told Australian radio on Wednesday that the official should have sent them off.

"I think there needs to be stronger penalties and certainly the ref should have sent someone off," Larkham said.

"For foul play I think a sin bin is not acceptable and certainly they need stronger rules in terms of rucking on the head or anything like that."

Larkham also hinted that his ongoing injury problems had forced him to seriously consider the option of an early retirement.

Although just 25 and with three years to run on his current contract, the brilliant number 10 has been plagued by injuries.

He missed last year's entire domestic season before recovering in time to play in the World Cup then underwent knee surgery after returning home.

"Hopefully I can play out those three years without any more injuries and then that will probably do me," Larkham said.

"(But) I guess there comes a time where if it degenerates anymore, then I'm going to have to think about seriously retiring."