The Brazilians are currently leading Group C with 11 points, followed by Wydad Casablanca with nine points followed by Petro de Luanda on three points and USM Alger on two points.
Sundowns have not lost in five matches, including three away matches.
On Saturday, they drew 2-2 with Petro in Angola.
Petro gave Sundowns a run for their money almost winning the match. The Brazilians, however, equalised in injury time – courtesy of defender Motjeka Madisha.
The 2016 Champions had already qualified for the quarterfinals before playing against Petro. They will be joined by Wydad in the last eight.
Mosimane says they did not play hard to win.
– Report by Vincent Sitsula