Mahesh Bhupathi [Images] became the latest casualty on the Mumbai Open list when he pulled out of the doubles draw on Thursday due to a back injury.

Bhupathi and France's [Images] Fabrice Santoro were scheduled to play their first round match against the Serbian pair of Viktor Troicki and Boris Pashanski late Thursday night. Bhupathi had won the title last year partnering Croatia's Mario Ancic.

• Hewitt cruises into second round

"It's disappointing not only because I was defending the title, but also because it's my event," said the Indian doubles veteran.

"Looks like this is a season of injuries. I can't even walk without pain and will take 10 days to recover completely.

India's Purav Raja and Vivek Shokeen will take Bhupathi and Santoro's place.

Bhupathi also informed that he will be teaming up with Mark Knowles of the Bahamas for the Madrid and Paris Masters.

On the organisational problems at the ATP event in Mumbai, which have been exposed due to the intermittent rains, Bhupathi said more expertise is needed to run the tournament smoothly.

Thursday's results:

Second round: Nicolas Kiefer (Germany [Images]) beat Lu Yen-hsun (Taiwan) 6-3, 6-3; Fabrice Santoro (France) beat Nicolas Devilder (France) 2-6, 6-3, 6-2; Jarkko Nieminen (Finland) beat Toshihide Matsui (Japan [Images]) 6-0, 6-4.

First round: Ivan Navarro (Spain) beat Purav Raja (India) 6-4, 6-1; Lleyton Hewitt [Images] (Australia) beat Chen Ti (Taiwan) 6-3, 6-3; Boris Pasanski (Serbia) beat Sergio Roitman (Argentina) 1-6, 6-3, 6-3.