Hall of Famer recognizes rival's contributions.
Feliciano Lopez, Grigor Dimitrov and Milos Raonic recall life-altering decisions.
The ultimate rivals are enthusiastic allies.
The world No.12 will become a brand ambassador.
According to Tennis Australia the 21-year-old will seek help to reduce his ban from eight weeks to three.
Alexander Zverev cracked the Top 20 for the first time today.
It takes daring and skill to successfully lob 6'8" Kevin Anderson.