Conchita Martinez will return to the Tour in 2019 to coach World No.8 Karolina Pliskova.
The pair previously worked together during the 2018 US Open.
Australian Rennae Stubbs also remains on Pliskova's team, and will share duties with Martinez.
The Spanish coach is based in Tenerife, where the pair are preparing for next year, starting with the Sydney International and then the Australian Open.
"Karolina is a player with enormous physical potential, is very receptive to proposals for further growth and has a motivation for extraordinary work," said Martinez.