Tim Henman admits he does not know when he will be able to begin his preparations for the new tennis season.
The Briton withdrew from last week's Paris Masters having fractured the cartilage of his first rib.
"As it's a cartilage problem it's a bit more difficult to say with any certainty when it will heal completely.
"I've been getting some treatment on it but it's still a bit sore. Hopefully it will ease with time and my off-season work won't be adversely affected."
The 31-year-old told his website that a scan on Tuesday produced "positive" news after his comeback came to an abrupt end.
"I was in real pain in Paris and it was a bit of a worry," he said.
"Having worked so hard to get my back right it was frustrating to pick up this injury right at the end of the season.
"Obviously I'm not missing any tournaments now and I would've been having some time off anyway.
"But I want to make sure it's fully healed in the next two weeks so that I can start my preparations for next year."