Madison Keys is out of the ATX Open in Austin because a WTA rule is preventing her from competing in the tournament. When the entry list for the WTA 250 tournament in Austin was released, the American tennis star's name was on it.

Keys, who rose to world No. 7 after winning her first Grand Slam title, had entered the WTA 250-level ATX Open in Austin, Tex., which begins February 24. The American entered the tournament as world No. 21, with fellow American Jessica Pegula entering as world No. 6.

Due to an odd rule preventing more than top 10 player participating in a WTA 250 tournament, the ATX Open announced Tuesday that Keys will no longer be eligible to participate in the event. The Austin-based tournament already has No. 6 Jessica Pegula committed to play.

Madison Keys will not be able to compete at next month's ATX Open in Texas because of a WTA rule which states that only one top-10 player can feature in 250-level tournaments