- Gael Monfils ruled out of action until New Year
- Frenchman's ranking has dropped from seven to 47
- Knee problem prevented him playing at full power
- Tommy Haas records 500th career victory at Austrian Open
Gael Monfils will not play again this year after suffering an injury-ravaged 2012.
The Frenchman, who has slipped from seventh in the world down to 47th, missed four months of the season after struggling with a problem in his right knee.
Monfils missed the French Open, Wimbledon, Olympics and U.S. Open before making a return to action in September.
He made it through to the semifinals at Metz but was beaten in the first round in Stockholm earlier in the week after losing to world 435 Patrik Rosenholm.
"He doesn't have a problem with his knee but we decided there was no point in playing the rest of the year. We have already turned our attention to 2013," Monfils's coach Patrick Chamagne told AFP.
Elsewhere, Germany's Tommy Haas made history after winning his 500th career match.
Haas, 34, saw off Jesse Levine in the second round of the Austrian Open and joined a group of elite players to have achieved the feat.
Roger Federer (871 wins), Rafael Nadal (583) and Lleyton Hewitt (566) are just three of those to have made it, while Jimmy Connors is the all-time leader on (1,243).
Haas' achievement didn't go unnoticed as he was awarded a Fiat 500 retro car on court to celebrate his landmark victory.
"I really wanted to reach 500 wins, it was a goal for me at the start of the year," said Haas, who won in Vienna last year.
"To do it means a lot. It's been such a hard road, I had to play some good tennis.
"No one gives you anything on the ATP. And to do it here in Vienna where I won the title was spectacular.
"You have a lot of goals over the years and I've tried to reach mine. This is something great, because I wasn't really sure I could do it when I was playing last spring.
"I feel really fit now and playing good tennis. It really makes me proud, I want to thank my family, my team and those supporting me. This is something I can always look back on."
Second seed Janko Tipsarevic kept his hopes of winning a place at the London end of year ATP World Tour Finals with a 6-3 6-4 victory over Ernests Gulbis.
Tipsarevic is currently just one place outside the eight spaces for the showpiece conclusion to the calendar but is showing little sign of nerves.
"I try not to think of anything before me or behind me," he said.
"I cannot be affected by the fact that everyone is chasing me. All I can do is stay completely focussed on every point of every match. I cannot think about being ahead or behind."
Australia's Marinko Matosevic will face top seed Juan Martin Del Potro after defeating Dominic Thiem 6-3 7-6.
Del Potro, who returned to action following a month's lay-off with injury, came through a three hour match on Wednesday to book his place in the last eight.