The 2016 African champions need a win to reach the Last 16 of the continental club competition and will meet Horoya in their final Group C match at home next week.
According to the legendary Brazilians dribbling wizard, Sundowns are in a good position to reach the next stage and picks Sundowns to beat the Guinean side.
Coach Pitso Mosimane's men occupy third spot in the group with five points and will have to beat the second placed Horoya who have eight points.
“I think it's in their hands, they are playing at home and that Horoya side is not a bad team, they have good players such as (Ocansey) Mandela, it is in their hands and I am sure they will win comfortably at home,” Moosa told Goal on Sunday.
“Sadly they can't win the group now, but they cannot afford to lose that match, that will be a blow for the country and Sundowns,” he added.
“I am not really concerned with their defensive errors because I think the guy (Anas El Asbahi) who scored for Wydad (Casablanca) doesn't score many goals and he could have caught (Denis) Onyango off guard, but it was a good shot,” said the former Bafana Bafana midfielder.
“I think they had a great campaign last season away from home and maybe it's time to do better at home now – I am sure they will fix everything when the match comes,” said Moosa.
“My only concern is to see what plan will Horoya come with because they need a draw and the game will be tough in that regard,” reacted the 49-year-old.
“They will be cautious, but I am hoping Sundowns will have a good game and I also believe they are yet to settle upfront because there is no Percy (Tau) now, but let's be positive,” responded the 1996 African champion.
“Like I said, Horoya is not a bad team and I watched them in their 2-2 draw against Sundowns and they play good football,” he recalled.
“I think it is also because they have good development structures as a country, but Sundowns will definitely make the home ground advantage count on the day because if they lose they will wait for next year and that is not good,” continued the former midfielder.
“The Yellow nation must come on board, intimidate the Horoya team and ensure they go back to Guinea with nothing in their hands – it's a do or die for everyone associated with Sundowns,” he concluded.