PHOENIX — Just before 3:30 p.m. at Chase Field, two of baseball’s most coveted relievers exited through the front door of the visiting clubhouse. It had been half an hour since the San Diego Padres concluded another trade deadline by pulling off the kind of deal that A.J. Preller has made throughout this decade.In virtually every example, the direction has been unmistakable.“We’re trying to win,” said Preller, the Padres’ president of baseball operations. “We don’t apologize for it. We’re trying to win championships. We’re trying to get to the postseason and do it year after year.”So, after leaving to attend a pitchers’ meeting Monday afternoon — and after weeks of rampant speculation — Mason Miller and Adrian Morejon returned through the same door. They were not going anywhere. Neither was anyone else.The Padres had kept their roster intact and added, by Preller’s standards, in modest fashion. Desperate for rotation upgrades, they traded two of their best prospects for rental starter Robbie Ray. Later, with minutes to spare, they traded their top pitching prospect for rental starter Casey Mize and infielder Gage Workman. San Diego ultimately did not line up a deal for the proven left-handed hitter Preller sought. Another acquisition, reliever Hunter Stratton, registered as a footnote.Still, it wasn’t exactly a safe trade deadline under baseball’s most aggressive general manager. The Padres — once on the verge of disaster; recently emboldened by an 8-1 surge — never appeared to come close to trading potential free agents such as Morejon, Ty France and Michael King. With their postseason odds still well below 50 percent, opting to replenish a shallow farm system might have been the shrewdest move.