The Milwaukee Bucks can offer Giannis Antetokounmpo the supermax extension this summer. If Giannis doesn't sign it, the Bucks star can become an unrestricted free agent in the offseason of 2021.

After talking to people around the league, ESPN's Brian Windhorst is convinced that the 2020 offseason star movement may hinge on whether or not Antetokounmpo signs the supermax with the Bucks:

“One of the things when I talk to executives out there that they say is if Giannis extends with the Bucks this summer — which depending on who you talk to is either a slam dunk or a real question — the Bucks certainly feel like they have a great chance to extend him this summer,” Windhorst said on his ESPN podcast (h/t Real GM).

“If he signs that supermax extension this summer and all of the teams that are sort of saving, you know, keeping their ammo dry for 2021 may begin to make action. They tell me this summer's star movement may be hinged on whether or not Giannis extends or not. If he extends, you'll all of a sudden see more action.”

By now, everyone in the NBA knows the Miami Heat are going to pursue Giannis in the summer of 2021 if the former MVP decides to enter unrestricted free agency. The Heat will try to sell Antetokounmpo on their culture and playing alongside Jimmy Butler and Bam Adebayo.

The Golden State Warriors and Toronto Raptors have also been rumored as potential suitors, and we can never count out the Los Angeles Lakers. There will also surely be other teams involved as well if it comes to that.

But again, this will only happen if Giannis doesn’t sign the supermax extension with the Bucks. By all accounts, Antetokounmpo loves playing for the Bucks and living in Milwaukee. He has said in the past he doesn’t like big-market cities such as New York or Los Angeles.

The Bucks also have a great shot of winning the East this season and ultimately winning the championship. For that to happen, the Bucks will need Khris Middleton and Eric Bledsoe to play at a high level once the playoffs start and be effective second and third options on offense, respectively, behind Antetokounmpo.

If Giannis winds up extending in Milwaukee, these other suitors will turn to their Plan Bs and look to make other moves to bolster their rosters.