NEW YORK — On Sunday, after a blown save, thanks to a bad error, closed out the New York Mets’ nightmarish first half, closer Devin Williams was asked what he’d do over the All-Star break to get a mental reset.“Anything but this,” he said without hesitation.“Anything but this” might as well be the motto for the Mets’ second half — anything but what befell them through a first half in which nothing went according to plan.A team expected to contend not just for the National League East but for the National League pennant instead finds itself deep in last place, an obvious seller ahead of the Aug. 3 trade deadline. President of baseball operations David Stearns’ transformative offseason has been nearly an oh-fer, with almost every one of his new acquisitions underperforming and/or missing significant time with an injury.Strangely, a disappointment of this magnitude only amplifies the importance of this second half for the Mets. Owner Steve Cohen has said he’s “extremely worried” about 2027, and the path back toward contention starts with what Stearns can acquire at the trade deadline and what New York shows over its final 65 games.Here are the other key storylines facing the Mets after the All-Star break:Who gets traded, and what comes back?It isn’t just that the Mets will be sellers at this trade deadline. It’s that their status as sellers is explicitly clear this far ahead of the deadline. Even the extremely disappointing 2023 team entered the final week before the deadline with a prayer of contending.That clarity can be beneficial. Preparing to sell at the deadline is more complex than preparing to buy, because it’s harder to know the ins and outs of other farm systems than your own. And the parity in the American League has limited the number of sellers for the moment, making this a better market for the Mets to peddle their wares.