He was the 1975 and 1977 Australian Open junior champion and the youngest player at age 17 to win the title since Ken Rosewall and John Newcombe.

[citation needed] Drewett began serving as Association of Tennis Professionals (ATP) Executive chairman and President on 1 January 2012.

[citation needed] On 14 January 2013, Drewett announced he would enter a transitional period as ATP Executive Chairman and President because of illness, after he was diagnosed with motor neuron disease (also known as ALS or Lou Gehrig's disease), writing: "It has been a privilege to serve as Executive Chairman and President of the ATP, an organization that I’ve been a part of for more than 35 years since I became a professional tennis player.

I hold the ATP very close to my heart, and it’s with sadness that I make the decision to enter this transition period due to my ill-health".

[5] There is also a memorial brass bust of Drewett at The Australian Open, Melbourne Park, reading 'A top-40 player, Australian Davis Cup representative, ATP Executive Chairman and President, Brad left an indelible mark on the sport he loved, ensuring our great game was in a better place than he found it.'.