World No. 2 Karolina Pliskova has hired Daniel Vallverdu as coach to replace Conchita Martinez. Martinez, on the other hand, reunited with her compatriot, two-time grand slam champion Garbine Muguruza for the 2020 season.

Having had a decent season, the 27-year Czech still decided to part ways with Martinez after she reached the semifinals of the WTA Finals earlier in November. Pliskova said it was time for her "to move forward."

Her best so far at the major tournaments was the U.S. Open final in 2016, when she lost to Angelique Kerber of Germany. She is now second in WTA singles ranking, without a grand slam title though. But that's exactly what she and her new coach aim for.

Vallverdu was previously part of the coaching teams of two-time Olympic Gold medalist and former World No.1 Andy Murray, three-time Grand Slam champion Stanislas Wawrinka, 2010 Wimbledon runner-up Tomas Berdych and 2009 U.S. Open champion Juan Martin Del Potro, and will aim to help Pliskova succeed at Grand Slams.

This wasn't the only change of coach for female tennis players recently. 

A few days ago, Ukraine's rising teenager and three-time titlist Dayana Yastremska announced Sascha Bajin, former hitting partner for Serena Williams and Victoria Azarenka and coach for Naomi Osaka, as her new coach for the 2020 season. He worked with France's Kristina Mladenovic after split with Osaka in February, and assisted her up 27 in WTA rankings.

Kiki Bertens of the Netherlands split with Raemon Sluiter and started working with coach Elise Tamaëla and future husband Remko de Rijke.

(With input from AP)