Lleyton Hewitt has taken a wild card into Houston, while fellow Australian Bernard Tomic has withdrawn from the clay-court event.

Also receiving a wild card into Houston is Janko Tipsarevic, a former Top 10 player. The Serb will be playing singles for the first time since October 2013 after being sidelined with a heel injury.

Tomic's withdrawal allows Tim Smyczek into the main draw of the ATP 250 event. Gael Monfils, who injured his hip in Miami, is unsure if he is playing.