PHOENIX -- Building a bullpen is among the hardest thing for a Major League Baseball general manager.
For every Mariano Rivera, who is almost robot-like with his consistency from year to year, there are dozens of examples of relievers whose performances vary wildly from one season to the next.
With that in mind, spending money in the free agent market on the bullpen has not been something D-backs GM Josh Byrnes has been eager to do during his tenure. That, though, is a philosophy that appears likely to change this offseason.
The D-backs are looking for a veteran reliever that could serve as a setup man for closer Chad Qualls, and they could add as many as two.
"I just think we're open to any way to make that a strength," Byrnes said of the 'pen. "When we pitch well out of the bullpen the last two years, those have been the times we've played well. Obviously, it's a very hard part of the roster to predict, but if we can bring in a guy or two in the offseason that can bring more power and depth back there, it's something we will take a look at."
Qualls pitched pretty well in his first year as closer before a knee injury prematurely ended his season. He is expected to make a full recovery and the D-backs are not inclined to look for a replacement.
Ideally, the veteran reliever the D-backs add would pitch primarily in the eighth inning. Guys like that -- think LaTroy Hawkins or former D-back Brandon Lyon -- are not cheap, but it sounds more and more like a price the D-backs are willing to pay for, they hope, more certainty.
Getting someone to pitch the eighth would allow the D-backs to slide Juan Gutierrez into the seventh inning role. The right-hander had a breakout year in 2009 and having him in the seventh, followed by someone in the eighth and then Qualls in the ninth, would be similar to how the D-backs' bullpen worked in 2007, when they had Tony Pena, Lyon and Jose Valverde at the back end of the 'pen.
The struggles of 2009 did allow the D-backs to get a look at and, in turn, develop some young relievers like lefties Clay Zavada and Daniel Schlereth, along with right-handers like Gutierrez and Esmerling Vasquez.
"I think a lot of guys got better as the season went on," Byrnes said.
In fact, the oddest part about the bullpen's struggles last year was that they did have good arms down there, or at least arms with potential that were able to gain valuable experience.
"That's what we accomplished this year in what was a tough year," manager A.J. Hinch said. "We were able to keep these guys in a position to develop and mature and now we should be able to reap the benefits from that."
Steve Gilbert is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.