PHOENIX -- It was quite a 48-hour period for Caleb Smith. The left-hander was informed on Tuesday that he had lost his spot in the rotation, only to be pressed back into action in a starter-like role Thursday when right-hander Taylor Widener was scratched ahead of the series opener vs. San Diego.

Matt Peacock technically started for the D-backs in Widener¡¯s place, but he was more of an opener with Smith picking up the bulk of the innings as the D-backs beat the Padres, 12-3, at Chase Field.

Smith, who allowed five runs in 1 1/3 innings against the Padres last Friday at Petco Park, this time gave up just one unearned run in 5 1/3 innings of relief.

"Caleb was nasty tonight," said infielder Josh Rojas, who went 4-for-5 at the plate. "I mean, his misses tonight were even really close. He was locating really well, his fastball was setting up his offspeed, which I think is really big for him. When he can locate that heater away to lefties and in to righties I think it makes his slider all that much better, and I think he was doing both of those tonight."

D-backs manager Torey Lovullo was informed a few hours before the game that Widener had let the team know that he was experiencing cold-like symptoms. As a COVID precaution, he was told to stay home.

Lovullo and his coaches decided to use the right-handed Peacock as an opener and then bring in Smith when they felt it would present a set of more favorable matchups.

The strategy almost backfired when Peacock gave up a double and triple to open the game and the Padres took a quick 2-0 lead.

Smith, though, came on with one out in the second and retired the first seven men he faced. That stabilized things for the D-backs and allowed their offense to get cranking against Yu Darvish, who left in the third after running into trouble and experiencing lower back tightness.

Arizona erased the Padres¡¯ advantage with a five-run third and followed it up with a three-run fourth.

Rojas and Carson Kelly each tallied four hits and two RBIs, while Pavin Smith also collected three hits and four RBIs of his own.

"I think that was the biggest thing tonight, [Darvish] wasn¡¯t commanding his fastball very well," Rojas said. "He was throwing a lot of a cutter/slider combination, David Peralta hit a splitter out. I think everybody had their own little way they were going to attack him, but for the most part the plan was to sit on that slider/cutter, sit soft, and make him get that heater in there for a strike."

Smith allowed just one unearned run, thanks to a dropped fly ball in the outfield by Ketel Marte. Lovullo relieved him with two outs and one on in the seventh.

Smith never likes to come out of the game in any circumstances, and as usual, had something to say to Lovullo.

"He just said, look, I need one more out to get through this inning," Lovullo said. "At that point in the game, we were kind of pushing the envelope, he had done his job and I just told him it was time. He never wants to come of games and that's one of the best parts about him -- he's very competitive."

Smith declined to speak with reporters after the game.

Tyler Gilbert is set to take Smith's spot in the rotation Saturday against the Padres, as the D-backs will have to wait and see what will happen with Widener.

Lovullo said Widener was in the process of going through the necessary COVID tests, but if for some reason he is out for a period of time, Smith certainly made a case that he could jump back in the rotation.