Roger Federer’s 2012 season isn’t off to the best of starts. (Fadi Al-Assaad/Reuters)

Only two days after Serena Williams pulled out of the Brisbane International tournament with a sprained ankle, Kim Clijsters retired from her semifinal match due to a hip injury. Meantime, men’s world No. 3 Roger Federer did not take the court for his semifinal at the Qatar Open on Friday, citing a back injury.

“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,” Federer said in a pre-match press conference. “I still have pain, and that’s why it was the only right decision, a difficult one for me.”

Federer, who said he still plans to play in this month’s Australian Open, knows he needs to be on top of his game following a season in which he finished outside the top two spots in the ATP year-end rankings for the first time since 2002.

The 30-year-old has been a fixture of good health during his near-decade-long run at the top of the men’s game, but has experienced back problems in the past.

“For Australia, I’m optimistic, just because it’s not very good but it isn’t crazy bad,” he said.

Kim Clijsters was forced to throw in the towel in Brisbane. (William West/AFP/Getty Images)

Clijsters won the 2011 Australian Open title to regain the No. 1 ranking for the first time in nearly five years, but shoulder and ankle injuries derailed her clay court season and forced her to withdraw from Wimbledon. At the Rogers Cup, she retired from her first match due to an abdominal injury that prevented her from defending her US Open title.

On Friday, the four-time grand slam winner took the opening set from Daniela Hantuchova in Brisbane but needed treatment early in the seceond set and retired after falling behind 3-1.

“I felt my left hip was getting tighter and tighter to the point I couldn’t move forward with my upper body,” she said. “So it was the smartest choice to try and not let it get any worse, to be ready for Melbourne.”

Despite the injuries, Federer and Clijsters made no mention of a brewing distaste for the sport they play.

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Federer pulls out of Qatar Open semifinals with back injury

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