OLYMPIC rowing champion Zac Purchase has been forced to pull out of the GB Rowing Teams' Winter Assessment in Boston, Lincolnshire today.

Purchase, who won the lightweight double scull with partner Mark Hunter in Beijing, is reported to be 'under the weather' and has been advised by the British team doctors to miss the event.

The assessment provides a chance for contenders outside of the current GB senior squad to stake their claim for a place.

But as a returning member of the British team, and defending Olympic champion, Purchase's absence will do little damage to his hopes of competing in London 2012.

Purchase has also claimed gold at the Rowing World Championships in the past two seasons, and recently claimed the Professional Sports Personality of the Year award at the Gloucestershire Media Sports Awards.

In comments posted on his website yesterday, Purchase said: "Gutted to have been withdrawn by the medics from this weekends trials.

"Was really looking forward to some proper racing again. Was going to be a good one too.

"Got to be careful in Olympic year though. London 2012 is more important!"

Double world champion Alex Gregory and Gloucester's 2010 World Champion Beth Rodford are set to compete in Boston.

However, Natasha Page from Hartpury is also unwell and won't be taking part in the trial.

And Nailsworth's Pete Reed also indicated yesterday that he was too unwell to take part.