Britain's Naiktha Bains and Jay Clarke were both beaten in the first round of qualifying for the Australian Open.
British number five Bains, 23, was beaten 6-1 6-2 by France's Tessah Andrianjafitrimo in Dubai as she tried to reach the main draw of a Grand Slam for the first time.
In the men's competition Clarke lost 6-2 6-4 against Taiwan's Tung-Lin Wu in Doha, Qatar.
Francesca Jones, Liam Broady and Harriet Dart are in action on Monday.
British number three Dart plays American Grace Min, Jones faces Monica Niculescu of Romania and Broady takes on France's Constant Lestienne.