Why it matters: When the NCAA tournament begins in March, three of the top five American draft prospects will be nowhere to be found, and it's not because their teams won't make the field — it's because they won't be in college.

• LaMelo Ball (No. 1 pick in ESPN+'s latest mock draft) is playing professionally in Australia.
• R.J. Hampton (No. 5) is playing professionally in New Zealand.
• Wiseman (No. 3) officially withdrew from Memphis this week.

The big picture: This isn't about the NCAA enforcing its rules and suspending Wiseman (Hardaway should have known better). Rather, it's about the nation's top recruit deciding that five months of training is more valuable to him than playing college basketball, notes USA Today's Dan Wolken.

• Wiseman still could have played the final 16 games for the 9-1 Tigers, who are currently ranked 11th in the country. He could have won a conference title, been named an All-American and maybe even played in the Final Four.
• You know he dreamed about that as a kid, too — cutting down the nets for his hometown university. And yet, he gave it all up in an instant. What does that say about college basketball's relevance in our culture? And what does it say about Wiseman's generation?

The bottom line: With the NBA's one-and-done rule expected to be abolished by 2022 and the G League beginning to resemble a true developmental league, college basketball could be in deep trouble once it's no longer a mandated pit stop.

• Even non-superstars could decide to skip college, especially if the G League continues to mature financially (players are reportedly unionizing, which could increase salaries) while the NCAA fights against athlete pay.
• And let's not forget the overseas route, where players can build an international fanbase in an increasingly global sport and prove to scouts that they can compete alongside current pros, all while getting paid.

What's next: With built-in student and alumni bases, college basketball has the G League beat when it comes to exposure, but even that benefit may be eroding.

• In an era where an athlete's brand is often built on social media rather than the court, Wiseman (167,000 Instagram followers) was going to be a marketable star on Day 1 in the NBA with or without college basketball and the platform it provides.

Go deeper: Top high school basketball players choose to play in Australia over college