Brockie was signed from SuperSport United in January after plundering 54 goals in a three-year spell for Matsatsantsa.
And while Brockie only opened his scoring account for Sundowns in a 3-1 league win over Free State Stars in November, he netted again with a cracking volley in a CAF Champions League encounter with Leones Vegetarianos last week.
Mosimane is naturally encouraged to see the New Zealander showing signs of regaining his old form.
"His contribution is good. Brockie is not 'Mshishi' [Zwane]," Mosimane said.
"We didn't buy him to come and dribble people. He is not Mshishi and will never be [Gaston] Sirino. He is a different kind of player.
"I don't know if you saw his goal in Equatorial Guinea. That's a sniper. Don't look for a playmaker.
"I am happy with what I have. I know what I have. I know what I brought [in]."
Downs will host Equatorial Guinea's Vegetarianos at Loftus Versfeld in Tshwane on Wednesday (19h00).
Mosimane's men won the first leg of the preliminary-round tie 2-0.