Kumalo sustained his injuries in his side's 1-0 loss to Absa Premiership leaders Kaizer Chiefs at FNB Stadium on 27 September.
"I picked it up in the first match against Chiefs which was the league game and I didn't take part in the Telkom Knockout last-16 also away and ever since I haven't kicked the ball," Kumalo says.
"It is both an ankle and knee injury and the likeliness of how long I will be out for, I'm not so sure.
"I went for the scan [on Saturday] and they took some water inside in my knee, but it is not something serious after doctors told me so that I will be back all right."
The ex-Moroka Swallows man is one of three players on loan at United from Mamelodi Sundowns, alongside Ntuthuko Mabaso and Kwanda Mngonyama.
And naturally Kumalo is hungry for game-time.
"Obviously it is not nice as a player if you not playing," says the 23-year-old.
"I came from Sundowns knowing I will get the game-time and now I find myself being injured and there's no player that can be happy with that.
"It's heartbreaking cause you are not contributing for the club and you not playing. But these are the tests that most playersdo find themselves in but also pass successfully by coming back strong.
"I need to be strong and I need to be positive so I can heal and be able to play games again."