Venus Williams could face
Azarenka in the second round should she win her first round match.
Serena Williams has won the Stanford hard court tournament the last two times she has competed in 2011 and 2012.
Stanford is a warm-up tournament for the US Open, the last of the four grand slams of tennis, which begins August 25th.
Williams took her first US Open title in 1999 as a 17 year old. The American then won in New York in 2002, 2008, 2012 and 2013.
However this year Williams struggled with a back injury in January at the Australian Open. She then looked tentative and error prone in both of her French Open and Wimbledon losses.
Williams has only won three WTA Tour tournaments to date this year; a low number for her but a WTA Tour season high so far this year. Maria Sharapova of Russia and Ivanovic share the WTA Tour leading number of tournaments won this year with Williams in a three way tie.
And despite her below par performance this year so far, Williams still tops the WTA Tour rankings 2,271 points ahead of the number two ranked Na Li of China.