British number one Johanna Konta has hired French coach Dimitri Zavialoff after a trial at the Kremlin Cup in Moscow last month.
Konta, 27, made the semi-finals of the tournament under Zavialoff's guidance.
The Frenchman was Stan Wawrinka's first coach, and also helped Timea Bacsinszky break into the world's top 10.
Konta, who recently parted company with American coach Michael Joyce, reached a career-high ranking of fourth last year but has dropped to 39th.
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Born in Sydney, Konta moved with her family to England aged 14, switching allegiance from Australia to Great Britain after becoming a British citizen in May 2012.