The Bafana Bafana international was stretchered off just 10 minutes into their MTN8 first-leg semifinal against Orlando Pirates on Saturday afternoon, a match that ended in a 1-1 draw.
"We are still awaiting a complete medical assessment on Zwane's injury, but we hope that it is not too serious.
"No one likes to lose a player to injury, especially if that player is Themba Zwane, someone with maturity and quality to play in the big matches."
Cardoso viewed the away goal at Pirates’ fortress as a silver lining in a match that could have gone either way.
The Sundowns coach also praised the Buccaneers for their fight and dismissed suggestions that the draw felt like a defeat for his side.
"It isn't a loss, and it doesn't feel like a loss, but we are disappointed to have conceded a goal.
"If you ask any coach if they would accept a draw before a match starts in Orlando, most coaches will accept it," noted Cardoso.
The game saw several enforced changes, which Cardoso suggested were a result of the match’s high intensity.”