07/25/2012 07:46 EDT | Updated 09/24/2012 05:12 EDT

Rowing great Ekaterina Karsten's rib injury hampering preparations for London Olympics

WINDSOR, England - Rowing great Ekaterina Karsten's bid to win a medal at a sixth straight Olympics is being hampered by a rib injury that is troubling her in practice.

The 40-year-old Belarusian broke a rib in April, forcing her out of the single sculls in the opening two World Cup regattas — in Belgrade, Serbia, and Lucerne, Switzerland.

The 1996 and 2000 Olympic champion battled through pain to win the final World Cup event in Munich last month but her injury isn't getting any better.

Karsten, nicknamed "Queen of the Single," says "in Munich, I was in less pain than I am right now."

She says the injury will not have healed by the time she competes in the heats for the single sculls on Saturday, the opening day of the Olympic regatta.