Gabuza was released from Pirates and joined Matsatsantsa along with midfielder Kudakwashe Mahachi.
Tembo revealed that Gabuza was working hard to revive his form in pre-season training ahead of their first game against Mamelodi Sundowns.
The United coach believes his side will “hurt” a lot of teams this season with Gabuza on their side.
Gabuza fell out with Pirates supporters after he threw his jersey into the booing crowd of supporters during a league game last year.
“Gabuza will give us something different when he go into attack because he is a number 9, who holds the ball he is strong in the air,” Said Tembo.
“He is an experienced striker who has played in the Caf Champions league with Pirates.
“I know it is rough for him because he was not happy where he was. We will try and build his confidence, there are positive signs in training. He is doing well.”