The 32-year-old's contract expires in June with SuperSport, who recently renewed the deals of centre-back Gould and defensive midfielder Letsholonyane.
Nkhatha, who joined Matsatsantsa from Kaizer Chiefs in January 2015, has struggled for game-time this season amid competition from the likes of Bradley Grobler, Thabo Mnyamane and Zimbabwean compatriot Evans Rusike.
The former Black Leopards hitman has not found the back of the net this season.
"Kingston Nkatha's contract is expiring," says United CEO Stan Matthews.
"We haven't sat down with him in terms of a renewal but that will also depend on the next three games."
Matthews adds: "Morgan has extended for next season. So it's been done.
"'Yeye' also did it a couple of months ago. Both of them will be with us next year."
Kaitano Tembo's side are a point above the drop zone, and next host high-flying Free State Stars at Lucas Moripe Stadium on April 25.