NATIONAL HARBOR, Md. -- As the Winter Meetings got underway Monday, the D-backs officially announced the signing of free-agent catcher Jeff Mathis to a two-year, $4 million deal, and general manager Mike Hazen and his staff spent the day working on more additions.
"We're doing our due diligence still," Hazen said. "Following up on things that started at the GM Meetings and through the period prior to this point. So we have things going on, but nothing close yet. We're having active conversations."
Most of those conversations figure to revolve around acquiring bullpen help, which is the chief need for the D-backs at this point. The exact number of arms they hope to acquire is not certain, but it sounds like they're hoping for more than one.
The cost of relief pitching is not cheap these days -- witness Mark Melancon agreeing to a four-year, $62 million contract with the Giants on Monday -- but so far the price has not surprised the D-backs, who figure to be looking a tier or two below that of Melancon, Aroldis Chapman and Kenley Jansen.

Hazen said the team was exploring both free agents and trades when it came to bullpen help.
"I think we would like somebody that pitches in the back end, certainly, to help out those younger guys back there," Hazen said. "And then I think we're open-minded about how the rest of the bullpen can come together. I think 'options' is probably one of the key words for us, giving us versatility. Left or right, certainly you can find right-handers who can get lefties out and vice versa. We're open-minded to how we can create that. I think volume is something that we're going to look at, making sure that we have a flexible and dynamic enough bullpen that we can make changes if we need to. You get into situations where you have to run your bullpen pretty hard some days, some weeks, and making sure you can withstand that is something that we're going to be focused on."
Though they seem optimistic about getting something done during these Meetings, the D-backs are also well aware that the market -- both for free agents and trades -- for relievers can easily slip into January.
Despite the addition of Mathis to go with Chris Herrmann, the D-backs are still open to acquiring another catcher. Herrmann's ability to play the infield corners as well as all three outfield positions makes carrying three catchers much easier.
"We feel like we have some games to cover back there," Hazen said. "So I would think we're going to make some other additions."