David Warner and Shane Watson must walk a fine line between banter and blow-up on Thursday, when Australia face India in their Cricket World Cup semi-final.

The stakes will be high for the entire Australian XI, which is expected to be unchanged after last Friday's win over Pakistan.

Victory and they advance to a trans-Tasman final on Sunday at the MCG.

Defeat and the past six weeks will have amounted to very little for the title favourites.

But Warner and Watson have the most to lose at the SCG.

If either match-winner has to face the music because of an on-field incident, they risk being banned for the tournament decider due to their rap sheet this summer.

"I don't want to get fined again or get suspended so I know I'm going to have to be even more diligent with what I say, when I say it and how I say it," Watson said.

"It's definitely going to be very hard-fought out there and we're going to have to be very careful not to step over the line."

The two sides had an often-heated Test series earlier this summer, with Watson and Warner involved in plenty of spats.

Warner has kept a lid on things since being fined for demanding Rohit Sharma speak English in a one-dayer at the MCG, where the right-hander insulted the Australian in Hindi.

"David will be fine. He knows the rules, as we all do," captain Michael Clarke said.

Sharma, who scored a century in his side's quarter-final win over Bangladesh, promised there would be no let-up in India's aggression.

"If there is a bit of banter going around, so be it," Sharma said.

"It's part of the game.

"There will be times where you'll see a lot of bowlers and fielders getting right in their faces.

"I just hope it doesn't cross the line."

Clarke agreed there would be sledging in the match, but noted it wasn't a focus for his side.

"It's really important we focus on what's important and that is playing our best cricket," he said.

Brian Lara and many other pundits have questioned the fines handed to Watson and Pakistan paceman Wahab Riaz after their lively duel last week.

ICC chief executive David Richardson, who joined Watson at a book launch with non-profit organisation Room to Read on Wednesday, defended the sanctions.

"I enjoyed the competitiveness ... it was just a pity it extended later in the game to something you wouldn't want your kids to see," he said.

Richardson rejected the tag of fun police and noted "generally player behaviour has been excellent".

"Things get heated; we actually like them to get heated from time to time," the former South African wicketkeeper said.

"Very competitive matches are good for the game.

"On the odd occasion, you lose your cool and you say something you shouldn't - perhaps you should get a fine or you might get suspended."

SEMI-FINAL

AUSTRALIA v INDIA

SCG (2.30pm)

TV: Live on WIN and Fox Sports 3

*Winner to play New Zealand in final on Sunday