Famed American tennis coach Nick Bollettieri, who helped to shape the careers of multiple Grand Slam winners, has died at the age of 91.
Bollettieri was regarded as a pioneer of tennis coaching, despite not playing professionally himself, and he opened the Nick Bollettieri Tennis Academy in Florida in 1978.
The former US Army First Lieutenant dropped out of law school to pursue a coaching career, and he was best remembered for his work with eight-time major winner Andre Agassi.
The likes of Maria Sharapova, Boris Becker, Jim Courier and Monica Seles were also taken under Bollettieri's wing during his celebrated time on the tour, and he worked with as many as 10 world number ones.
Bollettieri's coaching methods were criticized by athletes for a lack of focus on technical aspects, but the American pioneer was nevertheless a highly-respected figure within the sport and was described as one of the "most passionate coaches and advocates" by Billie Jean King.
Tributes poured in for Bollettieri following news of his death, with former student Tommy Haas writing on Instagram: "Thank you for your time, knowledge, commitment, expertise, the willingness to share your skill, your personal interest in mentoring me and giving me the best opportunity to follow my dreams."
Bollettieri was inducted into the International Tennis Hall of Fame in 2014.
