The Hawaii baseball team had the pieces but not the assembly in Thursday’s 4-3 road loss to UC Santa Barbara at Caesar Uyesaka Stadium.

A mostly left-hitting lineup and a by-the-book pitching change backfired on the Rainbow Warriors, who dropped to 26-23 overall and 10-12 in the Big West. The Gauchos improved to 26-27 and 9-13.

“We really couldn’t get any offense generated,” UH coach Mike Trapasso said in a telephone interview. “They got the hits when they needed them, and we didn’t. That was the story of the game. They got the timely hits with guys in scoring position and we did not late in the game.”

The ’Bows closed to 4-3 on Ethan Lopez’s RBI single in the ninth. With runners on first and second with one out, Chris Clements was summoned as the Gauchos’ third pitcher. Clements struck out Alex Baeza, then induced pinch hitter Chayce Ka‘aua to ground out to third for his second save.

Steve Ledesma, a right-handed senior, pitched eight innings, allowing six hits while striking out eight to improve to 7-3.

“I think we should have hit (Ledesma) better than we did,” Trapasso said. “He was solid today, so give him credit.”

Lopez, who went 3-for-4, tied it at 2 in the seventh on his sixth homer of the season, a two-run drive over the wall in right field. Second baseman Dustin Demeter accounted for two of the ’Bows’ eight hits.

“The lefties in our lineup struggled outside of Demeter,” said Trapasso, who started five left-swinging batters. “Our lefties did not see the ball well off their guys.”

Baeza, Maaki Yamazaki, Eric Ramirez and Jacob Sniffin were a combined 2-for-14.

UH left-hander Kash Koltermann, in his first start after 10 relief appearances, spaced nine hits through 62⁄3 innings. Koltermann exited after issuing a two-out double to Armani Smith, the Gauchos’ No. 9 hitter, with the score tied at 2 in the seventh.

With leadoff hitter Andrew Martinez set for his fourth plate appearance, Trapasso opted for a pitching change.

“It would be the fourth time through the lineup, and the last time he was getting tired,” Trapasso said of Koltermann. “The third time through the lineup, their guys were hitting pretty hard. He was giving up some loud outs.”

Trapasso said right-hander Matt Richardson would match up better against the Gauchos’ right-swinging hitters at the top of the order.

But Martinez drew a four-pitch walk from Richardson. Clay Fisher singled home Smith for a 3-2 lead, and Tommy Jew’s RBI single scored Martinez with the insurance run.

“Richardson comes in and gives up a four-pitch walk, and that guy ends up being the winning run,” Trapasso said. “It was the only (UH-issued) walk of the game. That goes to show you right there, you come out of the bullpen, you’ve gotta be throwing strikes and making quality pitches. (Richardson) was not sharp when he came out.”

Trapasso said the pitching change was “20/20 in hindsight.”

“If I leave (Koltermann) in and the guy pops up, then it was a great move,” Trapasso said. “You go right on right to Richardson, who had been throwing well, (and) when it works, it’s a good move. When it doesn’t, it’s a bad move. I guess it was a bad move.”

Dominic DeMiero had been a consideration to start for the ’Bows. But he had been suffering from a variety of ailments — “he checks all the boxes for feeling horrible,” Trapasso said — and spent the game resting in his hotel room. DeMiero’s illness assured Koltermann’s start.