The South African, who reached two Grand Slam finals and climbed to world No. 5 during his career, announced the news on social media Tuesday. 

Having worked with the likes of Maria Sakkari and Kevin Anderson, the former boxer is currently at work getting Australian Open finalist Jennifer Brady back in fighting shape.

Elsewhere, American rising stars Sebastian Korda and Brandon Nakashima both take on Top 16 seeds.

The South African has enjoyed a consistent season that already scored him wins over the likes of Rafael Nadal and Dominic Thiem.

Diego Schwartzman and Kevin Anderson ultimately completed their second-round clash on Arthur Ashe Stadium.

The American grabbed the last six points of the opening set before defeating the two-time Grand Slam finalist, 7-6 (4), 6-3, in Washington, D.C. on Monday.

The former world No. 5 returns to the Top 100 after winning his first ATP title in over two years.

The Roland Garros champion trails Simona Halep by the (practically) slimmest of margins.

The South African served his way through a valiant effort from Jenson Brooksby. 

Elsewhere Saturday, Casper Ruud defeated Roberto Carballes Baena in Bastad and is a win away from triumphing for the second time in 2021.