Bob Brett - a coach to Boris Becker, Goran Ivanisevic and Marin Cilic - has died of cancer at the age of 67.
The Australian helped Germany's Becker win Wimbledon, the US Open and the Australian Open between 1989 and 1991.
In his 2004 autobiography, Becker said Brett gave him "exactly what I needed" as a coach, demanding "willingness, discipline, willpower and punctuality".
Brett, who helped Ivanisevic reach three Grand Slam finals, opened a tennis academy in Italy, in 2002.