WP lose Du Plessis again
The Kings match was Du Plessis' first since coming back from a shoulder injury.
However, he will now face another spell on the sidelines after injuring his knee at the Nelson Mandela Bay Stadium.
Western Province head coach John Dobson confirmed that Du Plessis "tweaked" his anterior cruciate ligament and will be out for a couple of weeks.
Dobson also said that flank Rynhardt Elstadt might not be ready for his team's must-win clash against the Sharks at Newlands on Saturday.
Elstadt injured his ankle in training last week and was expected to make a full recovery ahead of this weekend's encounter.