A bowling all-rounder who bats lower down the order, 29-year-old Chris Morris has been managing the niggle for the last eight months. It worsened over the last two weeks resulting in Cricket South Africa's medical committee recommending an extended break from cricket activity to allow for a full recovery.
Morris has played two Tests, 15 ODIs and 11 T20 internationals. But the lanky all-rounder is slowly becoming an accomplished T20 specialist. He turned out for Surrey in July this year.
Cricket South Africa's team manager Dr Mohammed Moosajee said: "Chris has been carrying a chronic left knee patella tendon injury for the last eight months which we have treated and managed up to this point.
"The injury has flared up considerably over the last two weeks leaving us with no option but rest and rehabilitation to allow the knee time to fully recover."
Morris is expected to make a return in the Test series against Sri Lanka in December.
Meanwhile, the selectors have added Dwaine Pretorius to the squad for the series against Australia starting at SuperSport Park in Centurion on September 30.