Sanders, 25, from High Wycombe switched from the 400m hurdles to the flat in 2006, partly as a result of injuries.
Her decision proved a good one when she claimed world silver in Osaka last year, behind GB team-mate Christine Ohuruogu.
A niggling injury prevented her from running at July's trials, but if she can stay fit she has a good chance of medalling.
The semi-finals of the women's 400m take place on 18 August, with the final the following day at 1410 BST.
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