John Isner is hanging up the tennis shoes.

Isner announced Wednesday he will retire from professional tennis following the 2023 U.S. Open. "This transition won't be easy but I'm looking forward to every second of it with my amazing family," he wrote:

The American is known as one of the best servers in the history of the sport. He used his height at 6'10" to generate plenty of power and controlled a number of matches that way when he was at his peak.

He has the most aces in men's singles history with 14,411, which is 683 ahead of second-place Ivo Karlovic.

Isner set the record in July 2022 at Wimbledon, although he didn't seek out a massive celebration.

"Once I hit that number, whatever, not going to make an announcement or anything, but I'll know I have the record and it will be pretty cool," he said, per Alan Jewell of BBC Sport. "It's not going to put me in the Hall of Fame or anything like that, because that's not me. But I will be the all-time leader. I'll keep playing, keep adding to my total."

The 38-year-old turned pro in 2007 and, according to his ATP profile, has an all-time record of 488-316 with 16 overall titles and $19.5 million in prize money.

His last title came in 2021 in Atlanta, and he notably won the ATP Masters 1000 Miami in 2018.

While Isner never won a Grand Slam, he reached the quarterfinals at the U.S. Open and the semifinals at Wimbledon in 2018. He will also forever be associated with Wimbledon because he set the single-match mark of 113 aces in a 2010 victory over Nicolas Mahut.

That famous match lasted 11 hours and five minutes and was spread out across three different days before it ended at 70-68 in the fifth set. Howard Fendrich of the Associated Press noted a plaque outside of Court 18, where the match was played, honors the contest.

Isner has played 21 matches in 2023 with an 8-13 record. He is currently ranked No. 158.