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8/20/2013 10:53 P.M. ET

Marshall resumes throwing; Cueto waits on MRI

CINCINNATI -- Just over one month since a setback that shut him down, Reds reliever Sean Marshall resumed a throwing program on Monday.

"We were only out 60 feet, but we were starting up the process again," Reds head trainer Paul Lessard said on Tuesday. "He's been down for a while. If all goes well, we might speed it up vs. the offseason throwing program."

Marshall has been on the disabled list since May 24 with a sprained left shoulder. He had been making steady progress toward returning until mid-July, when he felt soreness following a bullpen session.

Assuming there aren't any issues, Marshall will throw again on Wednesday and continue to work on strengthening his shoulder.

Meanwhile, Reds rotation ace Johnny Cueto is scheduled to undergo an MRI exam on Friday to see if he has shown any improvement. Cueto, who has yet to resume throwing, went on the DL for a third time on June 29 because of a strained right lat muscle.

"If it shows improvement, he may start throwing as well," Lessard said. "But it all depends. His strength numbers are better than they have been. His last scan [last Friday] still showed the strain was maybe 75 percent healed. We're hoping it's a little closer to zero before we start a throwing program."

Back strain ends Cingrani's promising start

CINCINNATI -- After retiring the first 10 batters he faced in a 5-2 loss to the D-backs on Tuesday night, Reds starter Tony Cingrani exited in the fourth inning with a lower back strain. Although it had not been as severe as it was Tuesday, manager Dusty Baker said Cingrani had been hiding the issue from him and the training staff for a couple weeks.

"I felt it before," said Cingrani, who added that he could have pitched through the pain if his manager and trainers would have allowed. "It came on gradually. It hasn't been this bad, and it got pretty bad."

Cingrani blew through the first three innings on 36 pitches. However, Arizona's Martin Prado hit a solo home run with one out in the fourth inning for the D-backs' first hit of the game. Paul Goldschmidt then followed with a walk before Cingrani gave up a double to Aaron Hill after picking Goldschmidt off of first base.

It was then that Cingrani was joined on the mound by pitching coach Bryan Price, head trainer Paul Lessard and Baker, who took the ball from the 24-year-old left-hander, bringing the 16th start of his rookie season to an abrupt end.

"We were quite surprised," Baker said. "He was throwing the ball well, probably as well as he has all year, so for him to say something is wrong with him and for him not to continue, it had to be pretty serious.

"It shocked us all."

Entering Tuesday, Cingrani, who replaced the injured Johnny Cueto in the rotation, had gone 6-2 with a 2.60 ERA in 15 starts this season, while also contributing out of the bullpen.

Although Cingrani said he is sure he will take the mound for his next turn in the rotation, 28-year-old right-hander Greg Reynolds is a potential replacement if that's not the case. Reynolds, a former No. 2 overall pick in 2006, was called up once this season to pitch the second game of Cincinnati's doubleheader against the Giants on July 23. In five innings, Reynolds gave up five runs on eight hits and a walk.

For Triple-A Louisville this season, Reynolds has gone 12-3 with a 2.42 ERA, highlighted by a complete-game, two-hit shutout on June 21. He pitched Tuesday, which would make him available to take Cingrani's next scheduled start on Sunday against Milwaukee.

With Cueto already on the DL, though, Baker hopes Reynolds' services are not needed.

"We'll wait and see how he's doing in the morning," Baker said of Cingrani. "We certainly can't afford any more injuries on our starting staff going down the stretch here. Especially Tony, who is throwing the ball so well."

Starters putting relievers in position to succeed

CINCINNATI -- This late in the season, Dusty Baker is pleased with the shape his bullpen is in, and the Reds' skipper said as much following Monday's 5-3 win over the D-backs, calling the team's relievers strong.

Much of that, he said before Tuesday's game, is the result of Cincinnati's starting pitching, which ranked second in the Majors in innings pitched (783 1/3) and ERA (3.30) entering the second game of this week's four-game set against Arizona. With that, Baker has avoided overusing his bullpen and enjoyed some flexibility when it comes to who he puts on the mound in what situations.

Left-hander Manny Parra, who made his fifth straight scoreless appearance on Monday night, had an analogy ready to go when asked about relievers continually being put in positions to succeed rather than having to escape trouble created by the pitcher before them.

"I would look at it like going to a casino or something, where you're playing the game with the best odds," Parra said. "You're giving yourself the best chance to win, and when the starters go deep like they have been, you're able to use the guys in situations that, from previous stats, provide some sort of advantage for that pitcher. When you can do that, you're obviously giving yourself a better chance to perform."

Parra, who said he hasn't seen a bullpen receive this much rest in six Major League seasons, and his fellow relievers have certainly been performing quite well.

Before Tuesday's game, the bullpen hadn't given up a run in eight of the last nine games. In late June and early July, Reds relievers went 10 straight games without surrendering a run, helping contribute to the fifth best bullpen ERA (3.34) in the National League. As far as scoreless streaks go, J.J. Hoover leads the way, as he rode a 23-game scoreless stretch (club record for a right-hander) that covered 26 1/3 innings going into Tuesday.

According to right-hander Sam LeCure, though, Parra has been the biggest factor in the bullpen's success, as he recovered from a shaky first 12 appearances to build an ERA of just 0.78 in his last 14 outings. With Sean Marshall injured much of the season, Parra has been the team's primary left-hander out of the 'pen, limiting opposing lefties to a .188 batting average.

In reality, it's been a group effort. Closer Aroldis Chapman led the bullpen with 56 appearances before Tuesday, while no other reliever -- excluding Marshall -- had pitched in fewer than 35 games. Although Baker and his relievers were in agreement that starting pitching has been crucial, having a variety of relievers at the Reds' disposal hasn't hurt the bullpen's cause.

"Everybody down there has held their own and done a good job, I feel like, so we'll just see how it plays out," said LeCure, who also carried a five-game scoreless streak into Tuesday. "Everybody is going to be ready and understand that we're going to play tight games down the stretch. And all these games are important, so everybody is going to be on top of their game, I would imagine."

For Baker, he believes a fresher bullpen can be one of the deciding factors down the stretch for the Reds, who began Tuesday 2 1/2 games behind first-place Pittsburgh in the National League Central.

"It's huge," Baker said. "When they get worn down, they're worn down, unless you have a whole bunch of reinforcements like some organizations do. They can flip-flop guys in and out, like St. Louis has or like Pittsburgh has. We're depending on what we have."

Double take: Duo turns critical DP in clutch

CINCINNATI -- There wasn't much time to think, only react, for the Reds' middle infield duo of Zack Cozart and Brandon Phillips in the ninth inning on Monday. Their turning of a slick double play helped save a 5-3 victory over the D-backs.

Against closer Aroldis Chapman, Wil Nieves bounced a high hopper toward shortstop. Cozart lunged to his right to pick up the ball and made a tough throw across his body to Phillips. As runner Jason Kubel barreled in with a slide into second base, Phillips made a nice leaping throw to Joey Votto at first base that barely beat Nieves.

"When he hit it, I knew Nieves the catcher was running," Cozart said on Tuesday. "I told myself if I make a good throw to Brandon, we can turn this. I was trying to concentrate on not getting Brandon killed."

From zero outs to two outs, the double play proved clutch. Chapman gave up another single before closing out the win and notching his 31st save. The Reds rank 30th out of 30 teams in the Majors in turning double plays this season, but Monday's 6-4-3 play was about as good as it gets.

"It's one of those that's just weird," Cozart said. "You don't really work on that one too much. It's a slow roller. You catch it and have to completely turn your whole body. You have to almost act like you're going to throw it into center field to get it to go perfect. If you try to throw it straight to second base, it's going to tail off. It was tough, but Brandon turned it good and it was a big play for us."

Worth noting

Bronson Arroyo once against did not walk a batter and struck out six during his six-innings start and a 5-3 win over Arizona on Monday. According to the Elias Sports Bureau, Arroyo became the first Reds pitcher since 1900 to produce at least six strikeouts without a walk in three consecutive starts. He has gone 22 2/3 consecutive innings without walking a batter.

Mark Sheldon is a reporter for MLB.com. Read his blog, Mark My Word, and follow him on Twitter @m_sheldon. Jeremy Warnemuende is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.