The Brazilians are unbeaten in 25 games in the league.
Speaking during a media open day in Naturena this week, Castro said Amakhosi have prepared well for this clash.
“The confidence is high,” Castro said. “We are preparing well. We are winning the games. We are scoring. There’s a new mentality and challenge.”
“We all know that this is a big game for us. We need to take it like a cup final if we want to be on top of the table. We all know the quality Sundowns has. We need to be alert and try to do our best on the field,” added the former Sundowns striker.
Chiefs are currently sixth on the log with 21 points in 15 games, while Sundowns are fifth with 22 points in 12 games.