Nikolay Davydenko pulled out of the season-opening tournament yesterday due to a left heel injury.

Davydenko added that he had been carrying this injury for a while. "I first had this pain in Shanghai. But it went away after a few days and I played in Abu Dhabi last week. It comes back whenever I play. I could have asked for a few days rest and continued but I am sure the pain will come back," the top seed said on a rain-affected third day of the tournament.

Asked whether he had experienced pain on Tuesday after his first round match, Davydenko said, "I was fine last night but today morning I couldn't run or play tennis. So I have thought of returning home early and get an MRI done." The Russian also announced his withdrawal from the Australian Open, which begins on January 19.

With Davydenko's withdrawal and second seed Stanislas Wawrinka's loss to Flavio Cipolla on Tuesday, the tournament is bereft of its top two seeds.

Davydenko pulling out means Leander Paes' doubles partner Lukas Dlouhy gets a walkover in to Round Three.