Legendary tennis coach Nick Bollettieri has died at the age of 91.

The American, who coached the likes of Andre Agassi, Serena Williams, Maria Sharapova and Boris Becker, passed away on Sunday.

He founded the Nick Bollettieri Tennis Academy, now the IMG Academy, and long since gained a reputation of being one of the most iconic coaches in the sport.

Tommy Haas, who was also coached by Bollettieri, paid an emotional tribute to him on Monday.

The German posted on Instagram: "So many memories, I am not sure where to begin. Nickiiiii, that's how I have called you for the longest time.

"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.

"You were a dreamer and a doer, and a pioneer in our sport, truly one of a kind.

"I surely will miss you around the academy, our tennis talks, miss showing of [sic] your tan, white teeth and body fat, miss watching you do Tai Chi, miss playing golf with you watching you try to cheat, eating a Snickers bar and running for the bushes, and hearing all about your plans even at the age of 91.

"Thanks again for everything……..

"RIP Nickiiiii."

Monica Seles and Jim Courier were among the other players who were coached by Bollettieri.