Williams cut her right foot on broken glass at a restaurant shortly after winning Wimbledon. The tour said last week she needed surgery and would miss three tournaments leading up to the Open.
On Monday, tour spokesman Andrew Walker said Williams is questionable for the final Grand Slam of the year. Williams' return to the Open has been widely anticipated because of her tumultuous semifinal loss there last year, when she threw a tirade at a line judge at the end of a match against Kim Clijsters and was fined a record $82,500.
Because of the injury, Williams is missing the entire World Team Tennis season with the Washington Kastles. Her team said she cut the bottom of her foot and needed stitches. "Hey guys I'm doing better," Williams tweeted Monday. "Thanks for all the love." On Sunday night she tweeted: "can't wait to get out of bed & back on the courts & do what i do best!"
Ranked No. 1, Williams won her fourth Wimbledon crown and 13th major title July 3. The injury occurred shortly thereafter in Europe and at first was not believed to be serious. After hurting her foot, Williams played in an exhibition in Brussels on July 8 against Clijsters before a world-record tennis crowd of 35,681.
Williams attended a WTT match the next night in Glen Falls, N.Y., and did not play but briefly discussed her injury with reporters. When asked how she was able to play against Clijsters, Williams said, "Those Belgian doctors and waffles."
Clijsters said she knew before the exhibition that Williams was hurt pretty seriously. "I saw her before we started but she didn't go into how it happened," Clijsters said. "I told her how much I admired her for coming out there. A lot of players in her situation wouldn't have done it." Williams subsequently withdrew from upcoming tournaments in Istanbul, Cincinnati and Montreal. The last of those, at Montreal, begins Aug. 16, and the U.S. Open starts Aug. 30.
"You want the best players to be out there, especially at the U.S. Open," Clijsters said. "It would be sad not to have Serena there." After winning the Australian Open at the end of January, Williams was sidelined through April because of an injured left knee.
* AP Sports Writers Steven Win and Melissa Murphy in New York contributed to this report.