Chiefs recently acquired the Colombian striker from title rivals Mamelodi Sundowns, along with January recruits Siphelele Ntshangase and Kabelo Mahlasela from Baroka and Bloemfontein Celtic respectively.
Ntshangase made his debut in the 2-1 win over Polokwane City at FNB Stadium on the weekend, while fellow midfielder Mahlasela will have to wait some time for his bow as he suffered a knee injury on his first day of training at Naturena.
Castro is yet to feature for the Soweto giants but knows the pressure will be on him to deliver.
"Coming here, I need to work hard to complement the team," Castro said in a video shared on Twitter by Chiefs.
"I need to understand how the team is playing and I'm coming here to score goals, that is the way it is. So, the supporters expect me to score goals. That's why they bring me here, to help the team score goals and to win matches and to win trophies. I have the hunger to win trophies."
Castro pointed out fellow South American forward Gustavo Paez is helping him settle at the club.
"Some of the players, they were playing in the other team. So I got a good relationship with them, I know Paez. I speak with him the same language [Spanish]. It's nice and easy to be here."
The 28-year-old scored 15 goals in 57 appearances for the Brazilians.