Matt Williams takes the ball from Rafael Soriano Friday night. (Jonathan Newton/The Washington Post)

The Nationals signed Rafael Soriano to a two-year, $28 million contract in January 2013, adding him to a potential World Series contender with the hope he would record the final out of the season. In the final regular-season month of his deal, with the Nationals on the brink of a division title, Soriano will take the next two days off, regrouping as he tries to earn back his closer position before the playoffs begin.

Soriano will throw a bullpen session Monday with the intent of correcting mechanical issues that have led to a dismal second half, which culminated Friday night when he blew a three-run lead in the ninth inning by allowing home runs to Carlos Ruiz and light-hitting Ben Revere. In the meantime, Manager Matt Williams will determine his closer based on match-ups and game situation, choosing from the trio of Drew Storen, Tyler Clippard and Matt Thornton.

“It depends,” Manager Matt Williams said. “It depends on what kind of match-up we have. We’ve got options. It depends on their team. It depends on who’s used in other roles and how we want to do it during the course of the game. But there’s nobody in particular that we’re going to announce as the closer for the next few days. We’ve got guys with experience doing it, and any of them can. We’ll see how the games unfold.”

Soriano probably should have been an all-star this season – at the break, he had a 0.97 ERA and 22 saves. Since the break, though, he has imploded. In 21 appearances, Soriano has blown five saves with a 6.98 ERA. The league has hit .325 with a .917 OPS against him since the break.

Soriano will specifically work on his slider in his Monday bullpen session, a rarity for relievers, whose everyday schedule prevents them from practicing off a mound.

“That is the only pitch that be not good,” Soriano said. “The two home runs [Friday] were on hanging breaking pitch. I checked the video. It looked different.”

Soriano rarely looks at video of his pitching, but he did following Friday night’s meltdown. His agent, Scott Boras, reminded Soriano that his elbow was dropping too low on the slider, which causes the pitch to remain flat in the strike zone.

“My lawyer sent me a message telling me my elbow was a little too low and I need to raise it more,” Soriano said. “Like it happened when I was with the Yankees. I checked the video and it’s like that. The pitches are too different from what it looked like late last season and in 2012. Sometimes you lose it, and you don’t have someone to tell you how to do it it’s not going to work.”

Beyond his troublesome breaking pitch, Soriano insists he remains confident and feels strong physically.

“I was throwing 94, 93 mph,” he said. “If something was wrong, I wouldn’t have the velocity I’ve shown. Sometimes that happens.”

Soriano said he spoke with and trusts Williams. The two established a good line of communication in spring training and Soriano likes that about Williams. “When I say something to him, he tell me,” Soriano said. “Whatever you think it be the best for the team.”

Williams said Soriano could earn eventually back the closer role, but after his bullpen session “we’ll try to give him a little bit of a softer landing as he’s working through it.” The best-case scenario for Williams is Soriano reclaiming his position. But Soriano will need to prove himself again, though, to regain the closer spot before the playoffs.

“We’ll see how it goes,” Williams said. “There’s no tried-and-true plan to any of it, other than we want him to be confident when he goes back out there. We’d love him to be back to form and be able to shut down the  ninth inning for us. Of course. He’s been that all year. But he also realizes there’s an issue there with getting guys out lately. He’s going to work on that, and we’re going to help him as much as we can.”

Storen will be the most likely recipient of save chances. He has experience in the role and has been the Nationals’ best reliever this season. He said he would look forward to the chance to close again if it comes.

“Obviously, Sori has done a great job this year,” Storen said. “It’s one of those things, it’s really no different. The inning you throw changes, but you can’t do anything different. You don’t really get too caught up in it. At this point, I’ve done pretty much every role down there. It’s nothing new.”

The Nationals groomed Storen for the closer role since they drafted him with the 10th overall pick in 2009. He saved 43 games in 2011 and regained the role late in 2012 after returning from surgery to remove bone chips from his right elbow. The Nationals signed Soriano after Storen’s ghastly blown save in Game 5 of the National League Division Series.

Storen struggled in his set-up role at the outset of 2013. But since Storen returned from his demotion to Class AAA Syracuse on Aug. 16 last season, he has been one of the best relievers in baseball, posting a 1.38 ERA in 65 1/3 innings with 51 strikeouts, 17 walks and, more important for a closer candidate, only two home runs allowed.

“I think all the experiences, the highs and lows, are important,” Storen said. “It’s helped me do what I’ve done this year in the seventh. When you do different things in the bullpen, you get that experience. You can go out there and think you’re ready to throw the ninth. Unless you’ve done it before,  that’s when it kind of matters.”

Thornton, 37, has been a revelation since the Nationals claimed him off waivers from the New York Yankees in early August. He has allowed eight of 34 batters he’s faced to reach base and has yet to allow an earned run in 9 1/3 innings over 13 appearances. Thornton has never been a full-time closer in his 11-year career, but he has 23 career saves.

Clippard, an all-star this season, has been one of the most durable and reliable set-up relievers in baseball for the past five seasons, bringing consistency to a volatile position. He has a 2.04 ERA this year with 10.8 strikeouts per nine innings, mostly protecting leads the eighth inning. He took over the closer role in 2012 after Storen’s injury and saved 30 games.

“It wouldn’t necessarily be match-up the ninth,” Williams said. “It could be matching up the eighth or the seventh, depending on what match-ups we have. We wouldn’t limit ourselves to the ninth inning alone. We look at the situations and say, ‘Well, Clip is really good against lefties. So is Matt, for that matter.’ Drew has experience doing it and has been our seventh [inning] guy all year. So we have those options. We can look at how the game is at that point and who we want to use in those particular situations to work through it.”