PHOENIX — Reliever Roenis Elías has a tweaked hamstring, Washington Nationals General Manager Mike Rizzo said, and his short-term status remained uncertain Saturday at Chase Field.

Elías injured his hamstring Friday, in the Nationals’ 3-0 win over the Arizona Diamondbacks, when he came up limping after grounding out to first base. Elías, a left-handed reliever acquired by the Nationals before Wednesday’s trade deadline, had just six prior at-bats in his career. He was at the plate because Manager Dave Martinez wanted him to face the leadoff hitter in the next inning, and a short bench dissuaded Martinez from double-switching him into a different lineup spot.

But here was the catch: Martinez told Elías not to swing. He did anyway, bouncing a ball over the mound, and hurt himself trying to leg out an infield single. After the game, Martinez told reporters Elías was being treated for a cramp. Martinez maintained that Saturday, before Rizzo addressed the injury, and the manager added that Elías had yet to undergo an MRI exam. Elías spoke at his locker and mentioned both pulling his hamstring and just having a cramp.

Then Rizzo confirmed that his hamstring is the issue. Elías was added to the 25-man roster Friday and could head to the injured list if the Nationals believe he will miss any amount of time. They hope to have an MRI reading by the end of Saturday’s game or early Sunday. The team departs for a series in San Francisco after Sunday’s game.

“No, I just got here,” Rizzo said when asked Saturday afternoon whether he had a definitive update on Elías. “He tweaked his hamstring. Oftentimes those things that feel like a cramp early on linger into something a little more significant, but it doesn’t look to be serious. But we’re not sure where he’s at as far as . . . you know, we don’t want to be shorthanded for nine or 10 days. We’ll see. But it doesn’t mean to be too much beyond that kind of a thought process.”

That hinted at Rizzo’s logic moving forward: He doesn’t believe, at least publicly, that Elías’s hamstring tweak will require more than the minimum 10 days on the injured list. But if Elías is to miss a handful of games, he will want to call up another arm in his place. The Nationals’ current options on the 40-man roster are limited, and they don’t have another lefty reliever to plug in for Elías.

The three healthy relievers on their 40-man roster, and not already in the majors, are Kyle Barraclough, James Bourque and Kyle McGowin, who is currently starting games for the Class AA Harrisburg Senators. They also have an open 40-man roster spot after designating Tony Sipp for assignment on Friday, and could possibly use that to make an addition. The Nationals DFA’d Sipp to make room for their three new relievers, putting the 36-year-old lefty in a three-day waiver period. They DFA’d veterans Javy Guerra, Michael Blazek and Justin Miller earlier in the week, and they are now all with the Class AAA Fresno Grizzlies after clearing waivers.

That’s the bulk of internal options should Elías go to the IL, and none of them provide the situational lefty Washington traded for in Elias. Rizzo was encouraged by the start of Elías debut on Friday, when he retired the only two batters he faced with a fly out and strikeout. The rest created the sort of bullpen issue the GM hoped to avoid when he added three arms at the deadline.

“It’s unfortunate,” Rizzo said Saturday. “It’s hard to keep competitors from competing, and a lot of times instincts take over and unfortunately he felt something. So we’ll see where that takes us.”

LINEUPS

Nationals (58-51)

Trea Turner, SS

Adam Eaton, RF

Anthony Rendon, 3B

Juan Soto, LF

Kurt Suzuki, C

Brian Dozier, 2B

Gerardo Parra, 1B

Victor Robles, CF

Stephen Strasburg, P

Diamondbacks (54-56)

Jarrod Dyson, RF

Ketel Marte, CF

Eduardo Escobar, 2B

David Peralta, LF

Christian Walker, 1B

Jake Lamb, 3B

Nick Ahmed, SS

Alex Avila, C

Robbie Ray, P

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