According to the club, the 26-year-old suffered the injury during his first training session with his new teammates on Thursday.
He was unveiled as the club's second signing on a two-and-a-half-year deal on Wednesday afternoon.
“We are expecting the results when we get to Johannesburg on Monday,” Komphela told the media in the aftermath of Amakhosi's goalless draw at SuperSport United on Saturday night.
“By the looks of things, it looks like a long-term injury. It is a real pity that we will be losing Mahlasela; a dynamic player. Possibly for [the next] three months,” added Komphela.
The injury denied Mahlasela the chance to make his debut against Matsatsantsa, and he may have to wait at least until April to don the famous gold and black jersey, pending the results of the scan which will be made public by the club on Tuesday.
Meanwhile, Siphelele Ntshangase and Leonardo Castro are expected to link up with the team at the training grounds on Monday.
Should they be declared fit and ready to play, the duo could feature in next weekend's league match against Polokwane City at the FNB Stadium.