South African number one Kevin Anderson dropped one place to 35th in the latest Association of Tennis Professionals (ATP) world rankings released on Monday.
Anderson, the only South African ranked in the top 100, twisted an ankle and was forced to withdraw in the second set of his first-round match against American Sam Querrey at the ATP Masters event in Rome last week.
Rik de Voest climbed four places to 152nd despite being knocked out in the first round in Zagreb, Croatia last week.
Izak van der Merwe, who was also eliminated in the first round in Zagreb, fell one position to 138th. — Sapa