'Aggression's fine, we don't want robots'

The ongoing Australia tour of South Africa has been marred by on-field altercations with South African speedster Kagiso Rabada appealing against a two-Test ban for a shoulder barge on Aussie skipper Steve Smith in the second Test.

The 41-year-old Lee, a fearsome fast bowler during a sparkling career for Australia from 1999 to 2012, said that controlled aggression is good for the sport.

"The thing that I will say about that, in all honesty, is we don't want robots on the field," he said ahead of the T20 tri-series final between India and Bangladesh in Colombo on Sunday.

"Of course, there is a line that the players should not cross," Lee added, without offering any judgement on the incident involving Rabada, whose appeal is due to be heard by the International Cricket Council later on Monday.

"You don't racially vilify someone. You don't use excessive swearing or stuff that can upset children who are listening in. Other than that you've got to play hard cricket.

"Now I am not saying I agree with what happened and I am not saying that I don't agree with what happened, but what I can say is that we don't want to get into a stage where players can't even look at a batsman, batsman can't even look at a bowler without getting into trouble."

Rabada returned match figures of 11 for 150 at Port Elizabeth, an effort that was praised even by his opponents, but he stands to miss the final two Tests of the series, which is locked at 1-1, should his appeal fail.

Lee, who would regularly bowl at speeds of over 87 miles an hour (140 kph) during his peak, was full of praise for young Rabada's ability to bowl consistent lengths.

"He's good, I like him. Gets good shape on the ball," Lee said of the 22-year-old paceman who has already claimed 135 wickets in 28 Tests.