Kirk Nieuwenhuis traveled from one desert city to another on Tuesday and naturally went right for the pool. Without literally making a splash, Nieuwenhuis had a substantial night for the Mets. His 3-for-5, three-RBI performance — which included a two-run homer just outside the pool in right field — led a 9-0 demolition of the Diamondbacks at Chase Field, guaranteeing the Mets a winning road trip. But on a day the Mets placed Juan Lagares on the disabled list and recalled Nieuwenhuis, they were left with another concern, as Jennry Mejia departed after only five innings and 77 pitches after tearing a blister on his right middle finger. The torn blister is not expected to keep Mejia from making his next scheduled start, but the Mets will monitor the situation. The right-hander allowed only two hits over five shutout innings to rebound from a sluggish performance in Atlanta last Thursday. Mejia (2-0) retired the first nine batters he faced against the D’backs, and by the time he returned to the mound for the fourth, the Mets had a nine-run lead. Gonzalez Germen gave the Mets an extended relief appearance, pitching three shutout innings after Mejia departed. The Mets (7-7) will go for a three-game sweep of these listless D’backs on Wednesday, when Dillon Gee faces Brandon McCarthy. Already, the Mets have five victories in eight games on this road trip. Nieuwenhuis was batting .310 with two homers and eight RBIs at Triple-A Las Vegas after making a strong showing in spring training for the Mets. He credits changes he made to his swing over the winter for his recent success. “Watching film at home, there was just a lot of stuff going on,” Nieuwenhuis said before the game, referring to his swing. “I just shortened it up.” Manager Terry Collins liked what he saw from Nieuwenhuis in spring training.