09/13/2012 09:20 EDT | Updated 11/13/2012 05:12 EST

Aleksandra Wozniak hurts right shoulder, retires from Bell Challenge

QUEBEC CITY, Que. - Aleksandra Wozniak, Canada's top-ranked women's tennis player, injured her right shoulder during a warm-up session and was forced to withdraw from her match Thursday at the Bell Challenge.

The Blainville, Que., said she will have an MRI on Friday morning to see exactly what is wrong.

Melanie Oudin, ranked 107th in the world, will now move on directly to the quarter-finals.

Wozniak is 48th in the WTA rankings.