Coaching can be a game-changer said 2016 WTA Finals champion.
The Czech says he can no longer risk his health by playing Davis Cup.
Simona Halep will reportedly earn $2 million annually from Nike.
The Swiss could face Stan Wawrinka in the quarterfinals at the ABN Amro WTT.
ESPN gets broadcast rights throughout Spanish-speaking Latin America and the Caribbean to all 13 ATP World Tour 500 events.
Former No. 1 returns as Swiss Fed Cup coach.
The 23-time major champion has not been drawn to play singles on Saturday.