The Brazilians are placed 10th on the league standings after the first two rounds of matches, while United are in third spot.
However, Maritzburg have never won a league match against Sundowns in Pretoria, and Walters admits his team are in for a big test.
“Playing Sundowns is going to be a different ball game from our first two matches, against Tuks and AmaZulu,” Walters told maritzburgunited.co.za.
“So although we have done quite well in those games, we are going to need to step things up for this game. They have a lot of dangerous players. Teko Modise is always instrumental. Elias Pelembe could be back in the team, so too Nyasha Mushekwi.
“There is a lot of talent there, and we need to make sure we keep things tight and don’t give away anything at the back.
“If we can frustrate them, we could be in with a chance. We need to keep it contact and then look to hit on the counter – they are sometimes slow in getting back.”
Defender Byrone Hendricks is sidelined with a groin injury, other than that the Team of Choice have a clean bill of health for the match.