KEY POINTS:
Defending champion Philipp Kohlschreiber's withdrawal yesterday granted 2007 champion David Ferrer a free pass into today's semifinal against American Sam Querrey.
Having received a first round bye, second seed Ferrer has played just one match at the tournament so far, a 6-7 (3), 6-4, 6-4 second-round victory over Frenchman Marc Gicquel.
Kohlschreiber had been in good touch, defeating Juan Carlos Ferrero in a titanic three set encounter on Wednesday night to set up a quarter-final date with Ferrer.
But the German had been playing with a shoulder problem all week and had been dependent on high doses of anti-inflammatories to get through his matches without pain.
Yesterday morning he opted not to take the medication before a practice session and he quickly realised the injury was getting worse, prompting his decision to withdraw.
"Of course I am very sad that I cannot play," he said.
"The tournament is really just starting to get interesting. I had problems during the whole week and after the tough match [on Wednesday night] it got worse. The doctor and the physio said my tendon was very irritated and it is not getting better.
"It is not good for me to play every day with high doses of anti-inflammatories."
The 28th-ranked German was due to have an MRI yesterday and planned to stay in Auckland for the next few days while the injury was fully diagnosed.
He said he would await that diagnosis before deciding on whether to head to Melbourne to play in the Australian Open.
