PHOENIX — It was a busy Saturday night for the Washington Nationals’ front office, as they figured who was injured, who was available and how to best fill out the 25-man roster based on that information.

The result was four moves ahead of a 4:10 p.m. series finale with the Arizona Diamondbacks on Sunday. Reliever Roenis Elías went to the 10-day injured list with a right hamstring strain. Utility man Howie Kendrick went to the 10-day IL with a left hamstring strain. Reliever Javy Guerra, designated for assignment this past Wednesday, was added to the 40- and 25-man roster in Elías’s place. Outfielder Andrew Stevenson was recalled from the Class AA Harrisburg Senators for Kendrick.

This is not the most banged-up the Nationals have been this season. There was a stretch in April and May when they were without Ryan Zimmerman, Matt Adams, Anthony Rendon, Trea Turner, Juan Soto and a couple of relievers. But the active roster is certainly thinned, with Max Scherzer still out with lingering shoulder issues, Zimmerman back on the IL with plantar fasciitis in his right foot, the same injury as before, and now Elías and Kendrick on the shelf for the foreseeable future.

Their rotation this week in San Francisco is Erick Fedde on Monday, Aníbal Sánchez on Tuesday and Joe Ross on Wednesday. Scherzer could have been activated Monday but was still building up strength at Chase Field on Sunday. He has yet to throw off a mound since he faced the Colorado Rockies on July 25. Kendrick, placed on the IL retroactive to Thursday, can be activated on Aug. 11 at the earliest. He began the season on the IL with a left hamstring strain he suffered in spring training back in March.

Kendrick was scratched from a start Friday when hamstring pain flared up during his pregame jog in the outfield. Without Kendrick and Zimmerman, Manager Dave Martinez will have to lean on Adams as his everyday first baseman. Recalling Stevenson then gives Martinez another left-handed pinch-hitting option off the bench and an extra outfielder when Gerardo Parra has to moonlight at first.

Elías can’t return until Aug. 14. He played catch in right field before first pitch Sunday.

“It’s a mild strain. I talked to him today. He said he felt better. He doesn’t think it will take long,” Martinez said of Elías. “I told him: ‘We’ve got a great training staff. They’ll get you ready. When you’re ready, you’re in there. But let’s make sure you’re 100 percent.’ ”

The Elías injury is most troubling because of how it occurred. The left-hander, acquired before the trade deadline Wednesday, hit for himself in the Nationals’ 3-0 win here Friday night. Martinez instructed him multiple times not to swing, but instincts took over, and Elías did anyway. Then he hit a chopper over the mound, sprinted toward first and wound up grabbing his right hamstring a step away from first base. Washington initially treated it as a cramp, according to Martinez, but there were multiple mentions of a hamstring strain. An MRI exam revealed a strain, and that only continued a roller-coaster week for Guerra.

The 33-year-old right-hander was designated for assignment by the Nationals to make room for the three relievers they added at the deadline. He was then placed in a three-day waiver period, in which any team could have added him, but cleared Friday. He had two options at that point — become a free agent or accept a minor league assignment from Washington — and Guerra chose to stay with the organization that added him back in May. He was assigned to the Class AAA Fresno Grizzlies, but he never made it to the team.

Guerra lives in Arizona in the offseason, about 20 minutes north of Chase Field, so he went home with his wife and 2-year-old son. They watched the Nationals face the Diamondbacks on TV on Friday and Saturday. Then Guerra received a call, another twist in this season, and headed back to the ballpark.

“It’s always a tough one. I think you always want to explore other options just because you’re kind of at that point where you kind of need to figure it out,” Guerra said Sunday at a locker with his name on it. “But for me, the clubhouse had a lot to do with it. I just enjoy being here; everything about being here was a lot of fun. I enjoyed my time, so made it easy to stick around.”

LINEUPS

Nationals (58-52)

Trea Turner, SS

Adam Eaton, RF

Anthony Rendon, 3B

Juan Soto, LF

Matt Adams, 1B

Brian Dozier, 2B

Gerardo Parra, CF

Yan Gomes, C

Patrick Corbin, P

Diamondbacks (55-56)

Tim Locastro, LF

Ketel Marte, CF

Eduardo Escobar, 3B

Christian Walker, 1B

Adam Jones, RF

Wilmer Flores, 2B

Nick Ahmed, SS

Carson Kelly, C

Taylor Clarke, P