Usain Bolt ruled out for rest of season

London: World 100 metres record holder Usain Bolt will not run again this season because of a back injury, his agent said on Tuesday.

Bolt, beaten by American Tyson Gay in Stockholm last Friday, had been due to compete in the Diamond League meetings in Zurich and Brussels this month.

Triple Olympic champion Bolt was examined on Monday by a Munich doctor who found a problem with the Jamaican's lower back, which if not treated could cause injury to his hamstring or calf muscles.

"With a view to his future career we believe further treatment to loosen his back followed by a period of rest will be in his best interest," Bolt's agent Ricky Simms said in a statement.

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Bolt, 23, had been troubled by an Achilles tendon problem this season but an MRI scan showed that injury was now healed.

"I am very disappointed to miss two of the top meetings on the circuit -- Zurich and Brussels -- but trust that it is better for me not to take any risks this year," said Bolt.

"2011 and 2012 are very important championship years and I hope to be back fully fit and healthy," he added in reference to next year's world championships in Daegu and the London Olympics.

Bolt's shock defeat in Stockholm was his first in a 100 metres final in over two years.

He had been due to face Gay and former world record holder Asafa Powell over 100 metres at the final Diamond League meeting in Brussels on Aug. 27.