Pieterse said Burger, 37, was on a training ride early this morning when a minibus taxi drove through a red traffic light and hit her side-on.
“She suffered two punctured lungs, slight bleeding on the brain, a broken collarbone and all her ribs are broken on her left side,” Pieterse told In the Bunch today.
“Other than that, her legs and arms are still good.”
Pieterse said Burger went out “as usual” at 4.20 this morning to meet a bunch of cyclists at a busy intersection in Boksburg before a training ride, which was when the accident occurred.
He said there were three eye-witnesses who saw her get hit on her left side by the taxi.
Pieterse gave the assurance that Burger was being monitored by a “very good sports doctor”, Dr Richard Brink, who used to be a part of the Olympic Committee.
“He personally came through and is assisted by a team of another two doctors. They just need to evaluate her condition over the next two days and see how it goes.
“She is obviously a little sedated at the moment and she is currently on a ventilator to restrict her to the minimum of pain.”
He said, however, Burger had been speaking before she was sedated.
“Her eyes and hands are moving and she even kicked her blankets off earlier when she was getting hot.
“If she’s stubborn [like that] then you know she’s still good. That is the fighter she is.
“The only way is to be positive and move forward.”
Pieterse extended his gratitude for all the emotional support he had received since the accident.
“I’ve had calls from all the teams she used to race for in Europe. The Dutch Sports Institute, who are at worlds at the moment, even sent a message.
“Thank you very much for the support from anybody anywhere who has reached out,” he said.
She started her season by winning the Fast One Cycle Race in January.
She was also crowned the South African national road champion in 2009 and won the Cape Town Cycle Tour in 2015.