This comes after the midfield enforcer was sent for an early shower upon receiving a second booking in Sundowns’ 2-1 loss to league rivals Kaizer Chiefs at Loftus Versfeld on Tuesday evening.
“It was careless and unacceptable for him to get the second yellow,” said Mosimane.
Mabunda first went into the referee’s book when he pushed Chiefs’ Joseph Molangoane following a rough tackle he made on Billiat – a challenge that irked Mosimane and his bench.
“It doesn’t matter what happened to Khama Billiat, he (Mabunda) has to control his emotions, he is a Bafana Bafana player, he can’t just lose his temper. He let the team down and we will fine him for that.”
The African Coach-of-the-Year went on to solely pin the blame for the defeat on Mabunda.
“In fact, that (the red card) cost us the game to be honest because we were still in it. He deserved to be sent off because it was no longer a game of tactics, it was emotions and integrity of the badge,” said Mosimane.
“It was an unacceptable challenge on Billiat, it was a two-feet tackle from behind, but you got to understand that this was a big game,” concluded the ex-Bafana mentor.