The 29-year-old was injured in the Betway Premiership club's 3-2 MTN8 quarter-final victory last week.
He sat out of Tuesday's tense encounter where Sphelele Mkhulise netted a late brace at the Mbombela Stadium for all three points.
Cardoso expressed his disappointment in the manner of Mokoena's injury, as he felt the player was uncerimoniously hacked down.
Speaking after the game, the Brazilians boss told SuperSport: "Teboho Mokoena was today out for the match [vs TS Galaxy].
"I think that it's important that South Africa understands that we have to protect our players.
"We cannot come from the World Cup and [a player] make [injury] contact off the ball with a national hero when he plays his first match on South African soil, we allow such aggressive action on him without even being penalised. It's a rough one, very rough one. The player [Polokwane City player], he was not even yellow carded.
“But this is the injury that has prevented Teboho Mokoena. It was not even yellow card this action.”
Sundowns next play Kaizer Chiefs at the FNB Stadium on Saturday.
