ATP Tour Rank: No. 1️⃣4️⃣4️⃣ Universal Tennis Rank: No. 4️⃣2️⃣ What he's done since last summer: Won the Champaign, Columbus, and Noumea Challengers When (not if) J.J. Wolf finally appears on the game's biggest stages, you won’t want to miss this promising prospect.

When the 21-year-old catches fire, he’s an unstoppable force—one yet to hit the ATP tour.