No club can (wtf kind of laws do you have down under?). They took an optimistic and risky path with treatment instead of surgery, and hope he gets back in time for WC. It didnt work out, its an injury, it needs to be dealt with the best means possible. Their first option turned to be not enough even as temporary solution, so now go for the permanent one.
Even if he had taken the surgery a month ago it would take most of this year to fully recover from it. Hope for his sake he recovers quick and can make the WC. But most importantly that the surgery is a permanent solution to what ails him.