It's all fun and games outside the field for Kaizer Chiefs forward Leonardo Castro and his countrymen across town at Mamelodi Sundowns.

But the dinner meetings, friendly chats and all will take the back seat when Castro clashes against centre-back Ricardo Nascimento at FNB Stadium tomorrow (3.30pm).

"I know most of the players from Sundowns and they also know me. So it's not easy when we know each other," said Castro, who played for the Brazilians from 2015-2018 before switching to Amakhosi.

"We don't talk about the game, but just about our partnerships [friendships], because outside the field I'm friends with the South American players at Sundowns.

"We're so close with [Jose Ali] Meza, [Gaston] Sirino and Nascimento," he said.

Castro, who has five goals in 16 matches in all competitions this season, is expecting a good match from both teams.

"I think it's going to be a good game and we need to concentrate the whole game, and take the chances, but also close our back so we don't concede goals," he said.

On new coach Ernst Middendorp, Castro added that the German has hit the ground running and the players understand what he wants hence they've been getting the results.

"In terms of training sessions, he's got the structure for the players and that has made a difference."

But this is no doubt their toughest challenge since Middendorp's arrival.