SAN FRANCISCO -- A change is coming to the D-backs' rotation.

Left-hander Caleb Smith will be transitioning back to the bullpen, manager Torey Lovullo announced Tuesday.

"It’s a hard decision, obviously,” Lovullo said. “He’s had some very good meaningful games as a starter, but I felt like it was a way for him to reload, readjust and do the things that he did last time.”

Lovullo did not announce what Arizona will do in Smith’s place, but with an off-day Monday, he did not rule out the possibility of skipping that start entirely.

It’s been a bumpy year for Smith, to say the least, one in which he’s oscillated between roles.

Smith began the season in the starting rotation, but was jettisoned to relief duty after allowing four runs (three earned) across three innings in his first start.

An early transition to the bullpen likely wasn’t in the cards for Smith, but he made the most of the opportunity, becoming a reliable late-game, multi-inning reliever. In April and May as a reliever, Smith had a 2.70 ERA across 30 innings with 36 strikeouts to 13 walks.

That performance was enough to land Smith back in the starting rotation on June 1. He was effective in June, allowing 10 runs across 31 1/3 innings (2.87 ERA) with 35 strikeouts.

Since that solid June, however, things have gone downhill, and quickly. In four starts in July, Smith had a 9.61 ERA across 19 2/3 innings with as many runs as strikeouts (21).

Smith’s last two starts have been even worse. Against the Dodgers and Padres, Smith could not get through the second inning. Not only did Smith allow five runs in each outing, but he allowed a combined 11 walks in those appearances.

Strangely enough, free passes have plagued Smith more as a starter than as a reliever. As a starter, Smith walked 6.32 batters per nine innings. As a reliever, he only walked 3.90 batters per nine innings, still a high number -- it would be the most walks per nine inning in a season in which he’s thrown substantial innings -- but much more manageable territory.

“I just felt like after getting as much input as I possibly can, this was the right decision for the team,” Lovullo said. “I have to make decisions for the team and the best thing moving forward for Caleb.”

Rojas returns after monstrous rehab assignment

It’s safe to say that Josh Rojas’ rehab assignment was a thunderous success.

Fresh off a three-homer performance for Triple-A Reno on Sunday, Rojas was activated prior to Tuesday’s game against the Giants and slotted to hit eighth, his first appearance with Arizona since July 21.

“The day that he got hurt, it left a big void in what we were doing offensively,” Lovullo said. “He’s a catalyst. He’s someone that is engaged in every at-bat and finds a way to get on base. No matter where he’s hitting or what he’s doing or playing in the field, he’s going to make an impact. That’s the mindset he’s always had since I met him.”

Rojas, who appeared in three rehab games with Triple-A Reno, has been sorely missed. In 93 games, Rojas is slashing .268/.356/.438 with 10 home runs and seven steals, all while providing Arizona with positional versatility.

Rojas started wearing a protective sliding mitt in response to the dislocation of his left pinky, saying that the mitt worked fine and there was no pain on slides. Along with the mitt, Rojas said he experimented with gripping the bat in different ways to best protect his pinky.

“The first game was one grip, the second game was another grip. And then going into the third game, I didn’t like where I was at so I switched to go back to normal grip, just to see how it felt, and it felt good,” Rojas said. “I didn’t have any pain, and then obviously, the results told me everything I needed to know.”