Tony Sipp and Wander Suero will have elevated responsibilities now that Washington’s bullpen is back to seven relievers. (Jonathan Newton/The Washington Post)

When the Washington Nationals placed reliever Kyle Barraclough on the injured list Sunday with right radial nerve irritation, there were two ways to fill his spot on the 25-man roster.

They could have added another reliever — probably James Bourque or Kyle McGowin — to maintain an eight-man bullpen. Or they could have gone with a position player to bump their bench from four players to five. They went with the latter, recalling infielder Adrián Sanchez from Class AA Harrisburg, and that decision says a lot about where they are and what comes next.

The Nationals have carried an extra reliever pretty much all year. Their bullpen grew to eight in early April, when they swapped out Sanchez — then on the team in place of the injured Trea Turner — with Joe Ross. Washington needed Ross because Trevor Rosenthal was in the midst of a disastrous start that eventually led to a six-week rehab assignment. When Rosenthal went on the injured list and down to the minors, Manager Dave Martinez often kept eight relievers for four main reasons:

1. The bullpen began scrambling once Rosenthal couldn’t throw the ball over the plate, and it has since been trying to discover itself. So Martinez was trying, and still is trying, to find reliable relievers. The Nationals have gone through a carousel of arms, a handful of random minor league signings and even opportunities for Bourque (a rookie who debuted poorly in May), Dan Jennings (a veteran who was designated for assignment and opted for free agency), journeyman Javy Guerra (who’s currently sticking as a long man) and Tanner Rainey (who become a setup man).

2. A rash of injuries have created the need for constant options. Justin Miller (strained rotator cuff), Austen Williams (sprained AC joint in his right shoulder) and Koda Glover (strained forearm) are still on the IL, and now Barraclough joins them for at least 10 days.

3. When the back of the rotation was struggling, he often needed an option to back up both Aníbal Sánchez and Jeremy Hellickson. That meant the eighth spot was filled by Erick Fedde, who’s now starting in the injured Hellickson’s place, and McGowin.

4. Martinez rarely pinch-hits for his regulars, and because of that he thought he could carry an extra arm and go with four bench position players (including a backup catcher) for most games.

But now Martinez has five reserves, which raises a couple of questions: Why is this the right time for a bigger bench and shorter bullpen? And what does it mean for the Nationals as they begin a critical week with the Philadelphia Phillies and Atlanta Braves coming to town?

“I feel like Rosenthal has actually pitched better,” Martinez said in response to the first question, before his team improved to 33-38 with a 15-5 win over the Arizona Diamondbacks on Sunday. “So we have the lefties. With Javy, Rainey, [Wander] Suero, all those guys, it allows us to do that. It allows us to get another guy on the bench, which is kind of nice.”

In short, the bullpen is pitching better, so an extra arm isn’t needed — or needed as badly. Rosenthal is still far from high-leverage situations, and he was spotty in his most recent appearance, but Martinez at least feels like he can use him. The plan is for Rosenthal to take over the eighth, as he was signed to do.

More importantly, the 26-year-old Rainey quickly became a solid late-inning option. He has a 2.19 ERA in 13 appearances and pairs a high-90s fastball with a sharp slider. He has success when he can throw those pitches for strikes. Because his command has been sharp, Rainey is the seventh- or eighth-inning guy that Rosenthal and Barraclough have failed to be. Even if Suero has been inconsistent, and Rosenthal is still a question mark, Rainey’s results have allowed his teammates to settle in.

Having one fewer reliever, while a sign of Martinez’s increasing confidence in this group, will make it harder for him to manage the bullpen. Even though Nationals relievers have pitched the fewest innings in baseball and still have MLB’s worst bullpen ERA, it has often felt like a scramble, and many pitchers have been strained. Closer Sean Doolittle has already pitched 28⅔ innings. Lefty Matt Grace, who had been thriving in a matchup role, will need to expand back to making one- or multi-inning appearances. Suero, who has struggled going back-to-back days, has no choice but to improve there. Tony Sipp’s usage will certainly spike, despite his up-and-down year, and that will test the 35-year-old lefty.

But now weigh those potential drawbacks against the benefits of having five reserves. Martinez has said that a four-man bench has kept him away from making late-game defensive substitutions when Washington holds a tight lead. It has occasionally kept him from pinch-hitting early, which pushes starters deeper, running up their pitch counts. And it has sapped him of a backup shortstop, making it so Turner has started every game since returning from a broken right index finger May 17. Anthony Rendon has rarely sat, either, which is by design, but Sanchez is capable of spelling him or Turner.

The Nationals came into the season with seven relievers and a five-man bench. That was before Rosenthal flopped, along with the team as a whole, now sitting in fourth place, 8½ games back of the Braves in the National League East. That was when the Nationals were a division favorite and a surefire contender, and optimism was high.

The initial roster construction with seven relievers and five bench players was based on an ideal. Now, for better or worse, the Nationals are back to that.

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