Diamondbacks manager Torey Lovullo said the club’s thinking with its rotation shuffle was driven by a desire to give right-hander Zac Gallen an extra day of rest.

“I think it comes down to Zac and what Zac’s needed,” Lovullo said. “Zac’s a little gassed.”

Gallen had been listed as the scheduled starter for Diamondbacks’ series finale against the Los Angeles Dodgers on Thursday, Sept. 25, but the team announced the night before that left-hander Jalen Beeks will pitch instead. Right-hander Nabil Crismatt is expected to work multiple innings in relief.

Gallen will pitch on Friday, Sept. 26, in the series opener against the San Diego Padres at Petco Park.

Lovullo noted that Gallen has been under the weather for each of his past two starts and the club wanted to be proactive to “give him a little landing space for his own physical body.”

Lovullo was asked if Gallen asked for the extra day.

“No,” he said. “That was us. That’s us reading the room and doing the best thing for the athlete.”

The decision gives the club a chance to send a lefty to the mound to match up with the Dodgers’ top sluggers, though Dodgers manager Dave Roberts countered by slightly tweaking his lineup.

Rather than having Shohei Ohtani, Mookie Betts and Freddie Freeman as his first three hitters, he dropped Freeman to the cleanup spot and moved Teoscar Hernandez into the No. 3 hole.

Crismatt spent about a month in the Diamondbacks’ rotation before the club moved to a four-man about 10 days ago. He has made just one relief appearance since Sept. 14, working one inning against the Phillies over the weekend.

“That’s a good question,” Lovullo said, when asked how many pitches Crismatt might be able to throw. “We were just arguing about that in my office. I don’t know that answer.

“We’re going to read and react the same way we always do. It’s going to be on him. If he’s out there and he’s effective we’re going to stay with him. If it starts to wobble a little bit — we have no margin for error, zip — we’ve got to move fast. That’ll be our mindset.”

—Nick Piecoro

Dodgers at Diamondbacks, 12:40 p.m., Ch. 34Diamondbacks LHP Jalen Beeks (5-2, 3.67) vs. Dodgers RHP Yoshinobu Yamamoto (11-8, 2.58)

At Chase Field: The Diamondbacks shifted the pitching plan after the game Tuesday, opting for a bullpen game for the series finale. Lefty reliever Beeks will be the opener and right-hander Nabil Crismatt is expected to log multiple innings in relief. … When the Diamondbacks shifted to a four-man rotation last week, they knew they needed to find a fifth starter for one of the final five games. Initially, that was thought to be on Saturday, Sept. 27. Instead, they have decided to do it against the Dodgers, while Zac Gallen, Eduardo Rodriguez and Brandon Pfaadt now line up to face the Padres. … Yamamoto has allowed only five earned runs on 11 hits over his past five starts combined, with 43 strikeouts and 11 walks. Six of those walks came in his most recent outing, on Sept. 18 against the San Francisco Giants. On Aug. 31, he allowed a run on four hits with 10 strikeouts against the Diamondbacks, pitching seven innings.

Coming up

Sept. 26: At San Diego, 6:40 p.m., Diamondbacks RHP Zac Gallen (13-14, 4.70) vs. Padres RHP Yu Darvish (4-5, 5.51).

Sept. 27: At San Diego, 5:40 p.m., Diamondbacks LHP Eduardo Rodriguez (9-8, 4.91) vs. Padres RHP Michael King (5-3, 3.57).

Sept. 28: At San Diego, 12:10 p.m., Diamondbacks RHP Brandon Pfaadt (13-8, 5.00) vs. Padres RHP Nick Pivetta (13-5, 2.87).

(This story has been updated to add new information.)