PHOENIX -- For the first time since his rookie season in 2009, Cliff Pennington played third base Sunday as Martin Prado was out of the D-backs' lineup for just the fourth game all year.
"We've been working him out there for several weeks now," D-backs manager Kirk Gibson said before the 4-2 loss to the Reds. "Just looking at the long season, sometimes you need to do different things."
Pennington appeared in nine games at third for the A's in 2008, committing one error in 20 chances.
Pennington made a costly error at third Sunday, booting a groundball off the bat of Devin Mesoraco in the second inning that eventually led to an unearned run.
Sunday marked Prado's first off-day since May 27. On two of the previous three occasions the 29-year-old was out the lineup, he ended up pinch-hitting later in the game. He did not play Sunday. Prado is batting just .167 (12-for-72) in June after hitting .313 in May.
"Prado has been great for us; he has overcome some frustrations," Gibson said. "Everybody knows he wants to do good because of the trade, but we need to get some other guys in there."
D-backs' Hill to return for road opener vs. Nats
PHOENIX -- Arizona will get a big boost to its lineup Tuesday when the club begins a 10-game road trip in Washington. D-backs manager Kirk Gibson said Aaron Hill would be activated from the disabled list after the team's 4-2 loss to the Reds.
To make room on the roster for the move Tuesday, Arizona optioned left-handed reliever Joe Paterson to Triple-A Reno.
Hill has been on the shelf with a broken left hand since April 15. He was hit by a pitch on the hand April 9 against the Pirates.
"It's been a long time," Hill said. "These guys have been doing a great job; it's been tough to see how much fun these guys are having."
In six rehab games with Triple-A Reno, the second baseman went 9-for-24 with eight runs and six RBIs.
"I took some good swings; the timing was there," Hill said. "I got the amount of at-bats I wanted, so I'm good. It's all about how you feel. Hits are always nice -- you never complain about a hit -- but you know when your swing is there and feeling good."
To help protect the healing bone, Hill wear will padded batting gloves at the plate. In 36 at-bats to start the season before getting hurt, the 31-year-old collected 11 hits including three doubles and two homers.
"It'll be awesome to get him back," Paul Goldschmidt said. "Obviously he's a very good player. We all know what he can do. It's good to get him back."
Paterson made two appearances out of the bullpen for Arizona, allowing a run on two hits over 2 1/3 innings.
Bullpen role requires adjustments by Spruill
PHOENIX -- Before making his Major League debut out of the bullpen Friday, Zeke Spruill had not pitched in relief in a regular-season game since 2010, when he was still in Class A. But that did not mean he was lacking experience as a reliever.
In Spring Training the last two seasons, Spruill pitched exclusively out of the bullpen. This year in D-backs camp, the right-hander worked seven Cactus League innings, allowing just one earned run on four hits.
"You have to adjust some, but I got used to it in Spring Training," Spruill said. "So when I got called up, I tried to recall whatever I did then and implement it here."
Spruill gave up a hit to the first batter he faced Friday but retired the next three Reds he faced to get out of the inning.
"It's really not much different for me," he said. "I get ready fast when I start, so I go through the same routine out of the bullpen; I just shorten it down a little bit."
As for whether Spruill paces himself differently when he knows he will toss only one inning, Spruill said, "I'm 100 percent effort every time I'm out there."
Spruill got his second taste of action in Sunday's 4-2 loss to the Reds, working 1 1/3 clean innings of relief and striking out one. He walked two batters but worked out of a jam by inducing a double play.
String of homers won't yet push Bell from closer role
PHOENIX -- Despite serving up a home run in his fifth straight outing Saturday, Heath Bell will remain the D-backs' closer for the time being.
"Pretty much the way it is, he's going to be our closer," D-backs manager Kirk Gibson said. "We want to get him turned around."
Armed with a one-run lead against the Reds, Bell gave up a two-run homer to Jay Bruce in the ninth inning, blowing his first save since May 12. He had converted nine consecutive opportunities before Saturday, but over his last five appearances he has surrendered a combined seven runs in four innings.
Bell struggled in the first week of the season as well, but from April 9 to June 7, he lowered his ERA from 15.43 to 3.28. After Saturday though, it is back up to 5.02.
"He's doing what he was doing earlier in the year; he's kind of gone back to that," Gibson said. "It's a little mechanical. He has to adjust it. You see him out there, he's virtually only throwing fastballs; he has no feel for his breaking ball. He doesn't have any direction on his fastball, either."
While Gibson is not ready to remove Bell from his ninth-inning role moving forward, the manager added that he might send out either David Hernandez or Brad Ziegler if the D-backs got in a save opportunity again Sunday.
"We'll see the situation," Gibson said. "Is the right thing to do to put [Bell] in the fire again, or give him a day off? I'm a strong advocate of defeating the beast. I don't know. We'll think about individual situations."
Once J.J. Putz (elbow) is ready to be activated off the disabled list, the closer conversations will become a moot point. The right-hander, who will take his place at the back end of the bullpen when he is healthy, is scheduled to pitch for Triple-A Reno on Monday and Tuesday before the club decides his next move.
Tyler Emerick is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.