Temba Bavuma believes there is a balance to be found to maintain the intensity of bowler versus batsman (1:07)

Kagiso Rabada, the South Africa fast bowler who will miss next week's second Test at Trent Bridge, is said to be "heartbroken" to have let down his team, according to his team-mate Temba Bavuma, after he was served with an automatic suspension by the ICC for accumulating four demerit points.

Rabada earned one demerit point for swearing at Ben Stokes after dismissing him for 56 in England's first innings, on top of three he already had for a shove on Sri Lanka's Niroshan Dickwella in an ODI in January.

"KG is quite an emotional character," said Bavuma. "The way he acted - he didn't act like that on purpose. He was aware of the consequences. It was just in the heat of the moment. He is quite heartbroken as he feels he has let down the team."

On the thorny issue of sledging, Bavuma added: "It's something I have had to endure from schoolboy cricket days. I see it as part and parcel of cricket.

"There's a fine balance that needs to be achieved. You don't want it to be completely taken away but you still want the respect of the game to be there. A balance needs to be achieved."

The ICC's code of conduct has come under scathing criticism from former South Africa captain Graeme Smith who disagreed strongly with the decision.

Though Smith understood the sanction was based on collective, not isolated incidents, he did not think the expletive uttered by Rabada, which was picked up on the stump mic, should have been punished that harshly.

"It's ridiculous," Smith told ESPNcricinfo. "No-one wrote about it, no-one spoke about it. It was only because it was on the stump mic that it's become a thing."

The incident occurred on the opening day of the first Test at Lord's when Rabada dismissed Stokes and told him to "f*** off", something Smith thought was not serious enough to earn Rabada another demerit point.

"It could have been handled better. I don't think it was aimed at Ben Stokes. I just think it was out of frustration. If it wasn't picked up by the stump mics he wouldn't have been done," Smith said on Test Match Special.

"There is obviously a line that the ICC have drawn and we need to stay on the right side of it," said England's James Anderson.

"When I watch games, I like having the stump mic there. It's the players' duty to be aware that is there and they turn it up quite loud sometimes."