It's only the second time in his career that the Swiss legend has withdrawn mid-tournament, and he's yet to withdraw during a match. Clearly, the decision has not been easy for him.
The risk is that he loses the momentum he had with his 20-match winning streak going back to Basel last year.
The upshot is that Federer hopes to be back at 100 percent in the middle of next week. Said Federer:
“I have a long journey in front of me going to Australia, but I hope maybe midweek next week I should be 100 percent again, but that's just guessing right now. We'll see how it goes.”
On the injury, he said:
“I hurt my back in my second-round match against Zemlja and just got a little bit better for the match against Seppi. I don't feel a whole lot of improvement for today, and I just don't think it's the right time to risk anything more right now. I still have pain, and that's why it was the only right decision, a difficult one for me.”
Federer certainly took the right decision. There's no good reason to risk further injury in Doha just 10 days before the Australian Open. Here's hoping to a speedy recovery prior to Melbourne.