Scarlets coach Wayne Pivac is not expecting to see Wales centre Jonathan Davies back playing this season.
The British and Irish Lions’ player of the series is still recovering from a serious foot injury sustained in Wales’ defeat by Australia last November.
“Obviously Jon will be chomping at the bit to try and get back on the field as soon as possible,” said Pivac.
“He’s progressing but it is one of those injuries that takes a long time to heal. If you come back too soon and re-do it, that can be disastrous.
“The smart money says to get it right and then have a full pre-season.”
Fellow test player Ball has not played since dislocating his shoulder against New Zealand in the autumn.
Pivac said: “He’s probably a couple of weeks behind where we would like him to be.
“I don’t think he’ll be right for the quarter final but we’ve got our fingers and toes crossed that he will be… he’s a quality player.”