The 20-year-old centre-back suffered the injury in training last month and has already missed the club's last four games.
Chicago Fire are currently in fourth place in the MLS Eastern Conference and most recently won their first game of the Leagues Cup at home against Necaxa.
Head coach Gregg Berhalter has now confirmed that Mbokazi will miss the rest of their games for the current campaign.
"Mbo being out for the year is a tough one," Berhalter said on IOL.
"It's really about the next person stepping up and being a team that's hard to score on. Closing the spaces, being compact.
"We're working on that now."
Since losing Mbokazi to injury, Fire lost 3-2 to Inter Miami and 3-1 to New York before wins over Charlotte, and Necaxa.
Chicago Fire winger Puso Dithejane has revealed how working alongside Robert Lewandowski is helping him improve his game, particularly when it comes to finishing and movement inside the box.
Bafana Bafana attacker Thapelo Maseko says he's honoured to have completed his move to F.C. Copenhagen.
Major League Soccer side New England Revolution have completed the signing of Queens Park Rangers defender Tylon Smith on loan.
Pitso Mosimane is set to make a sensational return to the Bafana Bafana hot seat after the South African Football Association's (SAFA) National Executive Committee (NEC) approved his appointment.
