With those pieces of business out of the way, Towers had just one area to address in terms of position players: a left-handed-hitting backup first baseman.
It's possible, but not necessarily likely, that could be taken care of before the Meetings even get under way as the club has been in discussions about bringing back Lyle Overbay to serve as a backup to Paul Goldschmidt.
"Still working on Overbay," Towers said. "I still think he's a good fit for us to go with Goldy. Once we do that, I think position player-wise we're covered, so it's really pitching."
When it comes to pitching, the D-backs' decision revolves around what to do about Joe Saunders.
The veteran is entering his final year of salary arbitration and is in line for a substantial raise from the $5.5 million he earned in 2011. That could be more than the D-backs would like to pay.
The organization has top pitching prospects like Jarrod Parker, Trevor Bauer and Tyler Skaggs that it feels could compete for rotation spots as soon as Spring Training. Plus, it already has Ian Kennedy, Daniel Hudson and Josh Collmenter penciled into the rotation, with Wade Miley, Barry Enright and Charles Brewer among those who could be competing for a spot.
Ideally, the D-backs would acquire a veteran or keep Saunders as insurance and to avoid having to rush any of the young pitchers.
"Probably go in looking at trade opportunities to acquire a starter and then working the phones on free agents as well," Towers said. "We may just stay within. [We'll be] just trying to get the lay of the land of what it would cost and could we upgrade or can't we."
Finding a free-agent starter that would sign a one-year deal and be an upgrade over Saunders seems unlikely. The D-backs initially showed interest in Hiroki Kuroda, but have seemingly cooled since the GM Meetings a couple of weeks ago.
So the D-backs will either decide to pay Saunders more than they would like for one year, or non-tender or trade him while picking up a veteran that would have a deal longer than just one year.
"To me, if we are going to commit a multiyear deal to a pitcher it's going to have to be a significant upgrade over what we've got," Towers said.
One thing for sure is Parker, Bauer or Skaggs are not going to be dealt.
"Kicking the tires on the pitching front from a trade standpoint and the same names keep coming up -- Skaggs, Parker -- and I'm not going to move those guys," he said.
Last year when he came to the Meetings, Towers was looking to overhaul the Majors' worst bullpen. This year, his goal when it comes to relievers is far more modest, thanks to solid performances by closer J.J. Putz and setup man David Hernandez, as well as Brad Ziegler, Bryan Shaw and lefty Joe Paterson.
The club is talking to right-hander Micah Owings about returning. He is arbitration-eligible and the club wants him back, but not at what he would make at the arbitration table.
While the bullpen would appear pretty well set, Towers -- known as a master bullpen builder -- is always on the lookout for relievers.
"Our bullpen is in much better shape," he said. "It would be nice to add to that. In a perfect world, all things being equal, it would be nice to have two lefties. But if not, another experienced guy that we could run out there in the seventh or eighth inning if Shaw or Ziegler or Hernandez needed a day, somebody who could pitch late in the game, add more depth to the late innings."
Last year, Towers was trying to jump-start a team that finished last two years in a row. This year, the D-backs are coming off a 94-win season and a National League West title.
"It's a good position to be in," Towers said. "We don't have to go into the Winter Meetings worried we don't have any starting pitchers or big holes in the bullpen. We have infield depth, we have outfield depth, we have bullpen depth and we've got young starting pitching that we think are an elite group that is close."