Should the Thunder trade Russell Westbrook? What can they get?

— -- What's next for the Oklahoma City Thunder after Monday's shocking news that star forward Kevin Durant is headed to the Golden State Warriors as a free agent?

Do they need to trade Russell Westbrook? And who could the Thunder get in a Westbrook trade?

With Westbrook poised for unrestricted free agency 12 months from now, the Thunder must consider moving him to rebuild with young talent and avoid the same fate with a second star. Whether that makes sense hinges in part on how competitive Oklahoma City could be without Durant and how many teams would be interested in acquiring Westbrook entering the final year of his contract.

Let's try to answer those questions to see what the Thunder do next.

Projecting the 2016-17 Thunder without Durant

Without Durant's cap hold on the books, Oklahoma City now has about $7 million in cap space, including the hold for restricted free agent Dion Waiters and the salary of backup guard Anthony Morrow, which is non-guaranteed through July 15.

At most, the Thunder could clear about $23 million in cap space, although it's unclear whether Oklahoma City could find anyone worth that money at this stage of free agency.

More likely, the Thunder will bring back Waiters and keep Morrow, perhaps using the remaining cap space to add another option at small forward. Based on the multiyear predictive version of ESPN's real plus-minus (RPM) and my projections for rookie Domantas Sabonis, here's what I foresee for that group.

Oklahoma City's plus-2.4 net rating would typically translate into about 47 wins. That would be good enough to put the Thunder in the battle for home-court advantage in the Western Conference along with teams such as the Memphis Grizzlies and up-and-coming Utah Jazz.

Why should we expect Oklahoma City to be better than 2014-15, when Durant missed 55 games and the Thunder missed the playoffs? First, Westbrook also was absent for much of that season. In games he finished that Durant missed, Oklahoma City went 22-17, a 46-win pace over a full season.

And remember, the stars weren't the only Thunder players to suffer injuries in 2014-15. Now-departed Serge Ibaka missed 18 games, Andre Roberson missed 15 and Steven Adams 11. Oklahoma City can expect to be healthier this year.

Still, given the number of suitors who will have max cap space again next season, a 47-win season and a loss in the first or second round might not be enough to convince Westbrook to re-sign. So what are the Thunder's alternatives?

Extend or trade Westbrook?

Oklahoma City does have an interesting option for trying to keep Westbrook beyond next season: renegotiating and extending his contract. Because Westbrook is making less than his $26.5 million max salary, the Thunder could offer him some of their cap space for a raise of nearly $9 million in exchange for Westbrook simultaneously extending his contract.

ESPN's Brian Windhorst reported Monday that Oklahoma City is considering such an offer. However, it's hard to see Westbrook going for an extension.

Even adding just one year to his contract would cost Westbrook an estimated $1.5 million in 2017-18 salary because the cap is set to jump again by a higher amount than the 7.5 percent raise the Thunder could offer. Westbrook also would be limited to signing for three additional years, whereas he could get four from another team or five from his current team as a free agent next summer.

The longer shot for Oklahoma City would be trying to clear enough cap space next summer to retain Westbrook and make a max offer to one of the other top free agents on the market. Clippers forward Blake Griffin, an Oklahoma native, is a natural target because of his ties to the market and because most of the other star free agents in 2017 are point guards like Chris Paul and Kyle Lowry.

If the Thunder don't add any additional 2017-18 salary this summer, they could get to the projected max by trading reserve Kyle Singler and declining the option on Mitch McGary's rookie contract (or subsequently trading him).

Still, that would be a risky proposition. There's no guarantee Westbrook and another star would be interested in playing together in Oklahoma City, and saving cap space would mean foregoing the chance to extend Adams, Roberson and Victor Oladipo this fall before they become restricted free agents.

And so we come to the possibility of a Westbrook trade. With so many teams striking out on the top names on the market this summer, there's plenty of money available and desire for a superstar, so I think a handful of teams would be willing to offer something approaching full value despite not having any guarantee of re-signing Westbrook themselves.

After all, they'd then be able to offer a five-year max if that's what Westbrook wants, plus they could take advantage of his relatively small cap hold to potentially attract other free agents.

Having failed to even get a meeting with Durant, the Lakers might be willing to offer 2014 No. 2 overall pick D'Angelo Russell as the centerpiece of a Westbrook trade, since Russell would probably be redundant if they signed Westbrook anyway.

The Boston Celtics could build an offer around Isaiah Thomas as a replacement point guard and the draft picks they have coming from the Brooklyn Nets.

And teams like the Orlando Magic and Phoenix Suns might look at trading their young talent for Westbrook as a way to jump-start the rebuilding process.

Having just said goodbye to one superstar, Oklahoma City surely doesn't want to give up another so quickly. But that process would be a lot less painful with young talent and picks coming back in return than it would be if Westbrook too leaves via free agency next year, leaving the Thunder with cap room they would struggle to spend.

If Westbrook is unwilling to extend his contract, a trade looks like the prudent move for Oklahoma City.