Free agency starts on July 1st this Friday. You can take a look at what his schedule is for meetings with teams that we know of. His list is reportedly comprised of the Thunder, the Boston Celtics, the Golden State Warriors, the Los Angeles Clippers, the Miami Heat and the San Antonio Spurs. The Vertical broke down what each club would have to do to clear out the necessary cap room to lure Durant to town and it's a good read.
I still think that the Thunder have to be the favorite to retain Durant. After all, they can pay him the most since he has full Bird rights, Russell Westbrook is still on the roster, they got a young and talented roster, a good coach in Billy Donovan and they just came within one game of the NBA Finals. And after the well-received trade of Serge Ibaka that netted them Victor Oladipo, Ersan Illyasova and rookie Domantas Sabonis, I think they got better. Of course, Westbrook is a free agent next offseason so perhaps Durant may not be inclined to re-sign long-term with OKC but lining up his free agency with Westbrook's would make sense.
Of course, the Warriors are really focused on trying to lure Durant to the Bay Area and supposedly their players were trying to recruit him during the season. Adding Durant to a core that features Stephen Curry, Klay Thompson and Draymond Green would make that team scary, and fun, as hell. Adding Durant to a team that only went 73-9 and lost the NBA Finals in seven games would immediately make them the championship favorites and considering that we know that Durant wants to play for a team that will immediately be a championship contender, that makes them the clear competition to the Thunder.
It seems like there is some distance from those two teams and the rest of the pack. The Spurs would be able to pair Durant with Kawhi Leonard and LaMarcus Aldridge, not to mention iconic head coach Gregg Popovich, and they showed a year ago that they are willing to make moves to bring in a star-caliber player as they did with Aldridge. That said, now that Tim Duncan has opted-in for next season by way of his player option, creating that necessary cap space is a little more difficult. But it's not improbable and the Spurs may just be championship contenders for as long as Popovich wants to stick around (and a player like Durant could encourage to hang on longer)
Of any team in the mix for Durant, the Clippers have the highest hurdles to manage thanks to the expensive contracts of Blake Griffin, DeAndre Jordan and Chris Paul. One of those players would have to be dealt (likely Griffin) and they'd have to bring Durant in via the sign-and-trade in all likelihood, which may not be something the Thunder are willing to do. Then they would have to virtually gut their bench to have the money available.
The Heat seem like the longest shot. After all, they don't have much cap room as is, their star player (Chris Bosh) is in a precarious injury situation, contract negotiations with Dwyane Wade are not going well and they also have to do with the free agency of Hassan Whiteside. Everybody loves South Beach and James made them the cool team to build a superteam but I would be pretty stunned if Durant were to head to Miami.
But the Celtics seem like a quality dark horse to bet on. They are a consistent playoff team as-is in the East, a young roster with some pieces, they have a very good coach-GM combination in Brad Stevens and Danny Ainge, they have the least to do to create room for the max contract that Durant warrants while also having space in the future to bring in more pieces as well as draft picks and they play in what is still an easier conference to navigate.
In the end if I were a betting man (and I now am), I see Durant returning to Oklahoma City for one more season and then enter free agency with Westbrook next year. That way they can make one more title push, as I think coming so close to getting to the Finals left them very hungry, and then move forward. But hey, should be an interesting weekend in the Hamptons.