South Africa's top tennis player, Kevin Anderson , has dropped five spots to No 32 on the official ATP rankings .
This follows Anderson's first round exit at last week's Cincinnati Masters, where he lost to Alexandr Dolgopolov of the Ukraine.
Anderson had jumped into the world's top 30 following his quarter-final run to the Montreal Masters, where he succumbed to eventual champion Alexander Zverev of Germany.
Anderson, whose highest ranking to date has been No 10 in 2015, will nevertheless be buoyed by his recent form after an injury-plagued 2016.
He is not in action at this week's Winston-Salem Open but should earn a seeding for year's final Grand Slam, the US Open, which starts in New York next week.
Top 10-ranked players Novak Djokovic, Stan Wawrinka and Kei Nishikori have already confirmed they won't participate at Flushing Meadows which opens some spots in the draw.
The top 32-ranked players get seedings at majors.