Sports Circle?? You mean Sports R/A, right??

OK If you start in the Sports R/A go all the way straight until you reach Al Corniche Street, make a right and keep on driving until you reach a traffic light, That's Grand Hamad Street. Make a right and a few hundred meters in your right hand you will see Souq Waqif.

Additional reference, check the link

http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=souq+waqif,+...

By the way if you don't have a car then jump into any Taxi, it can take you there.

Regards!!