This was revealed by City boss John Comitis to Phakaaathi on Thursday.
Mthembu was finally announced as a Ciity on Thursday after Phakaaathi reported that he had signed the day before.
“Siphelele is someone that plays with a lot of commitment on the field, you can’t question is commitment of the field,” Comitis told Phakaaathi.
“We needed a striker or player that could take the pressure off some players like (Ayanda) Patosi and Riyaad (Norodien) because he is a handful for defenders. Gift (Links), Patosi and Riyaad need a striker like him, who can take the pressure they need to play off someone like that.
Comitis is confident that Mthembu will form a good combination with Matthew Rusike in Benni McCarthy’s attack.
“We think Siphelele and Rusike will be a great combination on the field, we also have (Judas) Moseamedi in the mix and we need a striking department to be competitive.
“It won’t be the first time we take a player who is not at the forefront at his club and it pays off at a high level for us. We did it with Major (Lehlohonolo Majoro), we did it with (Robyn) Johannes they all game from the benches of teams.