American John Isner has announced he will retire after the US Open.
The 38-year-old, who has served a record 14,411 aces, has won 16 singles titles, reaching a career-high world ranking of eighth in 2018.
He also competed in the longest tennis match in history at Wimbledon in 2010, beating Nicolas Mahut 6-4 3-6 6-7 7-6 70-68 over 11 hours and five minutes.
"After 17 years on the ATP Tour, it's time to say goodbye to professional tennis," said Isner.
"This transition won't be easy but I'm looking forward to every second of it with my amazing family.