Bongani Khumalo faces six months out after rupturing his kneecap while on international duty.
The 27-year-old will undergo a knee operation this afternoon after being strechered off during South Africa’s 5-0 friendly defeat to Brazil last night.
Khumalo’s agent Glyn Binkin said: “Bongani will be having an operation early this afternoon, but he will likely be out for a lengthy period. Six months or so.
“Bongani is honestly the strongest player mentally that I’ve ever worked with.
“He has overcome many massive hurdles in his career to date, and sees this as yet another one to overcome.
“He is very upbeat and confident that he will bounce back even stronger.”
On-loan Tottenham defender Khumalo has been an almost ever present at the heart of Doncaster’s defence since arriving from White Hart Lane in the summer, making 32 appearances.
His injury setback comes just a week after skipper Rob Jones was also ruled for the rest of the season with a neck problem.
Khumalo’s Doncaster teammate Dean Furman played for the full 90 minutes at Soccer City in Johannesburg.