London - Andy Roddick said he was up and running again having spent the most boring weeks of his life laid up with the knee injury that kept him out of the ATP World Tour Finals.
The US world number six, who sustained the injury on October 13 during the Shanghai Masters, said it was tough to be watching all the action from the sidelines at the O2 Arena in London.
But the 27-year-old Wimbledon finalist said he was looking forward to being back to full fitness for the 2010 season.
"The injury, it's coming along well," the former world number one said.
"We're probably a little bit ahead of where we thought we would be. I've been able to run in a straight line, and hopefully next week I'll be able to get back out on the courts and practice.
"The two weeks after Shanghai were probably about the two most boring weeks of my life. Literally I was on a couch. You went from 20 minutes on ice, 20 minutes off. Not a whole lot. There wasn't a lot of walking to be done - or a lot of anything else, for that matter.
"The progress has been very good, especially in the last couple of weeks. I've been able to run in straight lines. Now it's just a matter of getting the lateral movement back.
"I'm thankful that I'm able to make a full recovery for next season."
Roddick's withdrawal from the season-ending top-eight tournament in London meant a call-up for Sweden's Robin Soderling.
"It is a different dynamic for me to be here and to be talking, not playing," Roddick said.
"You know, it was a lot easier to deal with for me not being at this tournament when I was home.
"But to be able to come here and see just the energy that's around it, just the great event that's being put on, I definitely am envious towards those guys out there, that they're able to play and participate in this event.
He added: "This is probably the toughest tournament to choose a winner in because it's a pretty neutral surface, everyone has the same deal going in."