John Isner New Coach: American Tennis Star Adds Famed Broadcaster To His Team [VIDEO]

The United States' brightest tennis hope isn't accepting his second-tier status on the ATP.

ATPWorldTour.com reported that the world's No. 19-ranked player - the top American - has hired former ATP player and current Tennis Channel broadcaster Justin Gimelstob as his coach.

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Gimelstob reached a career-high ranking of No. 9 in 2012 with former coach Mike Sell but felt a change was needed.

"I'm really excited to start working with Justin," Isner said. "He has so much experience within the tennis business and I've long respected his knowledge of the sport. I think it will be great for me to have a new perspective helping me with my game.

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"I had a great run with Mike and feel I really learned a lot from him throughout the course of our coaching relationship. I just thought it was time to try something new, and with Justin I believe I will have a strong, and passionate new voice on my team. In spending some time with Justin throughout the fall I have full confidence that he has a clear vision for my game and an understanding of what I need to do in order to play my best tennis."

Isner is best known for his marathon match against Nicolas Mahut in the first round at Wimbledon in 2010, winning the five-set match 6-4, 3-6, 6-7 (7), 7-6 (3). 70-68 that took three days and 11 hours, five minutes to complete. It is the longest match in tennis history.

The 37-year-old Gimelstob was a doubles specialist during his career who reached a singles ranking high of No. 63. He won 13 career doubles titles and earned a ranking of No. 18 in 2000.

"John is a very unique talent, a great guy both on and off the court and I am thrilled to be able to be a part of his team," Gimelstob said, according to the ATP. "Coaching is in my blood. My father and uncle were both basketball coaches and I had the good fortune of working with some of the best tennis coaches in the world during my career.

"I have the highest regard for the level of commitment coaching a player of John's pedigree entails. I am excited for the new challenge, and look forward to pursuing it with a player that I believe in so much. I have had a great relationship with John for years and think we will communicate really well as player and coach."