The coach said Van der Dussen and Bavuma, who injured his hamstring while batting in the third ODI against Pakistan in Centurion on Wednesday, are both doubtful for the T20 series that starts on Saturday at the Wanderers.
Van der Dussen, one of the star performers for the Proteas in the series, pulled out of the third ODI on Wednesday morning.
“Rassie has between a Grade I and Grade II quad strain so he’s probably out for 10 days,” said Boucher following his team’s defeat in the series decider.
“We hope for a quick turn-around but it would be stupid to try and push him, so he’s not likely to get on the park.”
Bavuma, who is in his first series as leader of the white-ball team, is also expected to miss the four-match T20 series.
“Temba is a tough guy but he’s hobbling in the changeroom and in quite a bit of pain, so I’m afraid it’s quite bad,” said Boucher.
“But those are the cards we’ve been dealt and we have to find a way.”
The Proteas are already without five key players in Quinton de Kock, David Miller, Kagiso Rabada, Anrich Nortje and Lungi Ngidi, who all left South Africa after the second ODI to play in the Indian Premier League which starts in the coming days in India.