Paul Sewald has, unquestionably, stabilized the Diamondbacks bullpen in the 11 months since he arrived in Arizona. He closed out six postseason wins last fall and was on the mound when they clinched a World Series berth for the first time in 22 years. Just seven days ago, he had a 0.54 ERA.

Yet there he was Monday night, walking off the mound at Chase Field to an outpouring of boos from every direction. For the third straight appearance, Sewald had blown a save, allowing a game-tying, two-run home run to Sean Murphy with two outs in the ninth. Two innings later, the Diamondbacks succumbed to defeat, losing 5-4 to the Braves and missing an opportunity to go over .500 for the first time in three months.

The Diamondbacks’ record over the past week can be split into two categories. When Sewald pitches, they are 0-3. When he does not pitch, they are 4-0. That is a stat no closer wants to see. Essentially single-handedly, he has prevented a nine-game win streak — the type of stretch the Diamondbacks have spent all season begging for.

'Unacceptable': Arizona Diamondbacks fans call for change at closer after another Paul Sewald blown save

Given Sewald’s production since the Diamondbacks acquired him at last year’s trade deadline, it’s a shocking turn.

From the time he joined the club until last Tuesday, the Diamondbacks were 42-6 when Sewald pitched, including the postseason. Despite a crucial collapse in Game 1 of the World Series, he had converted 30 of 33 save opportunities — better than Mariano Rivera’s career rate. The Diamondbacks could not reasonably have asked for more.

Over the past week, they could not have gotten less. On Tuesday, he allowed three straight two-out hits to turn a 5-4 lead over the Dodgers into a walk-off loss. On Friday, he allowed two homers in the span of three batters, creating a 10-8 loss out of an 8-7 lead. And on Monday, he allowed a two-out single to Eddie Rosario, followed by the soul-crushing home run to Murphy.

“You've just gotta finish innings,” manager Torey Lovullo said. “Made some really good pitches to get in that position and just a couple mistakes. … I’m still shaking my head.”

Lovullo said Sewald will remain his closer despite the blown saves. His other options have not been particularly inspiring recently. Ryan Thompson has surrendered a handful of key hits over the past few weeks and Justin Martinez allowed five hard-hit balls to the seven batters he faced Monday.

“I'm not ready to make that decision,” Lovullo said. “Paul's been an unbelievable closer for us and he will continue to get the baseball.”

As for why Sewald has encountered this brutal stretch, Lovullo could not come up with a unifying thread. His veteran closer, meanwhile, left the clubhouse before reporters entered. Sewald also declined to speak with reporters Friday in San Diego.

Gabriel Moreno, the Diamondbacks’ 24-year-old catcher, said that the fastball to Murphy was supposed to be above the zone and instead leaked down onto the outside edge of the plate. That has been a commonality in Sewald’s recent struggles. Last Tuesday, when he did speak with reporters, Sewald expressed frustration with an inability to elevate his fastball. On Friday, the game-tying home run came on a fastball that he left at the bottom of the zone with catcher Jose Herrera set up at the top.

For Sewald, that is a particularly devastating issue. He essentially only throws two pitches — the four-seam fastball and a sweeper. After spending four ineffective years with the Mets, he developed into an excellent closer in 2021 precisely because the Mariners taught him to throw fastballs high and sweepers down.

The second part of that equation has also evaded Sewald recently. In each of his three blown saves, his sweeper has had less side-to-side movement than it typically does. Instead of breaking across the plate and away from right-handed hitters, it’s staying inside, rendering it ineffective and forcing Sewald to rely even more heavily on his fastball.

Still, Sewald has shown some flashes of his normal self. On Monday, he induced two weak flyouts and struck out Travis d’Arnaud. Rosario’s single to set up the home run came on a fastball high above the zone, right where Sewald wanted it. Rosario had not managed a hit on a pitch so high all season.

Those moments illustrate why this stretch might not be prescriptive. Earlier this season, Cleveland's Hunter Gaddis blew three straight saves. Since then, he has a 0.33 ERA. Last year, Washington's Kyle Finnegan suffered the same ignominy. In his next 26 appearances, he allowed two runs.

Avoiding that variance, though, is the responsibility bestowed upon closers. Two weeks ago, Sewald said that his pitches had “not been nearly as good as we'd like them,” even though he had a sub-1.00 ERA at the time. Now, his fortune has swung the other way.

Monday, given the circumstances, felt particularly painful. Not only did the Diamondbacks have an opportunity to climb above .500 for the first time since April 3, but it could have come with a bright ray of optimism for the future. Yilber Diaz, one of their most exciting pitching prospects, worked six innings of one-run ball in his debut.

The day should have been about him. Instead, the Diamondbacks were left to deal with a newfound closer problem.

Previously: Diaz set to make MLB debut

Three key injured pitchers set to return to mound

Three injured Diamondbacks pitchers — Merrill Kelly, Eduardo Rodriguez and Jordan Montgomery — will all make a key step in their rehab progress Tuesday. Each is scheduled to throw a 20-25-pitch bullpen at Salt River Fields.

Montgomery, who hit the injured list a week ago with knee inflammation, is closest to a return. That could come shortly after the All-Star break.

The other two have been out for months — Kelly since April, Rodriguez since March — and will need more time to build up arm strength. Manager Torey Lovullo predicted that they will require three to four bullpen sessions. After that, they’ll move on to simulated games before beginning rehab assignments in the minor leagues.

At this point, Rodriguez appears slightly closer to a return than Kelly. Both are likely to join the Diamondbacks in August.

Drey Jameson back on the mound but not set for 2024 return

Right-hander Drey Jameson, who is working his way back from Tommy John surgery, is also throwing bullpen sessions at Salt River Fields — almost exactly 12 months after he tore his ulnar collateral ligament.

Jameson, though, is not going to return this season. The Diamondbacks’ goal is to prepare him to be at full strength for the start of spring training next February.

“Just continue to build up arm strength, work on delivery stuff, face some hitters and be ready for a normal offseason,” Lovullo said. “That's the most important thing.”

Short hop

Right-hander Brandon Pfaadt will make his scheduled start Thursday. He took a line drive off his ankle Saturday and exited the game, but he is feeling better and set to throw a bullpen session Tuesday ahead of Thursday’s start.

Tuesday's Diamondbacks-Braves pitching matchup

Braves at Diamondbacks, 6:40 p.m., Cox, Ch. 34

Diamondbacks RHP Zac Gallen (6-4, 3.06) vs. Braves LHP Chris Sale (11-3, 2.71).

At Chase Field: In Gallen's latest outing against the Dodgers on July 4, he allowed four hits and three runs through four innings and struck out four. ... This season, Gallen has a 3.06 ERA overall with 71 strikeouts and 19 walks in 67⅔ innings pitched. … Gallen’s start against the Dodgers was his second since coming off the injured list with a hamstring strain. He threw the seven fastest pitches of his career in the game. … For the most part, Gallen’s numbers this year have been in line with the past two years. He finished top five in NL Cy Young voting both seasons. … Sale, who was initially slated to start Monday, is enjoying his best and healthiest season in a long time. Through 16 starts, he has logged 99⅔ innings with only 19 walks and 127 strikeouts. … He faced the Diamondbacks in April, giving up two runs in 5⅓ innings in a no-decision. … Sale is holding opposing hitters to a .164 average and .233 slugging against his slider, a pitch that elicits whiffs on 41.8% of swings.

Coming up

Wednesday: At Chase Field, 6:40 p.m., Diamondbacks RHP Slade Cecconi (2-6, 6.10) vs. Braves RHP Charlie Morton (5-5, 3.96).

Thursday: At Chase Field, 6:40 p.m. Diamondbacks RHP Brandon Pfaadt (3-6, 4.19) vs Braves LHP Max Fried (7-4, 3.18).

Friday: At Chase Field, 6:40 p.m., Diamondbacks RHP Ryne Nelson (6-6, 5.08) vs. Blue Jays RHP Yariel Rodriguez (1-3, 3.68).

This article originally appeared on Arizona Republic: Sewald continues nightmare stretch with another blown save in loss