Emma Raducanu has pulled out of next week's WTA event in Monterrey after injury forced her to retire from a three-and-a-half-hour match in Guadalajara this week.
The US Open champion, 19, described it as a "small left leg injury" and said she has postponed her return in order to recover as well as possible.
Her match with Daria Saville was the longest on the WTA Tour this season.
She is scheduled to play next in Indian Wells in a fortnight's time.