Los Angeles - Rain washed out all matches scheduled for Tuesday at the US Men's Clay Court Championship, the ATP tournament in Houston, Texas.
Organisers said all remaining first-round singles matches would be completed on Wednesday.
That includes fifth-seeded Spaniard Fernando Verdasco taking on South African veteran Kevin Anderson and sixth-seeded Feliciano Lopez taking on Bjorn Fratangelo.
First-round play got underway on Monday when 39-year-old German Tommy Haas out-lasted 19-year-old American Reilly Opelka 7-6 (7/5), 4-6, 6-3.
Haas booked a second-round meeting with top-seeded American Jack Sock.
Defending champion Juan Monaco of Argentina was ousted on Monday, falling to German Dustin Brown 7-6 (9/7), 6-3.