Hill, who was acquired by Arizona from Toronto in August, has a club option for $8 million and it appears unlikely the D-backs will pick that up. However, they would like to have him back and will try to negotiate a new deal. Hill hit .315 in 33 games following the trade.
If they do bring Hill back, the D-backs would then focus their efforts on finding some depth in the infield to cover themselves should shortstop Stephen Drew take longer than expected to recover from July's ankle surgery.
If they are unable to reach an agreement with Hill, Arizona could shift Ryan Roberts from third base to second and then search for a third baseman, either via trade or the free-agent market.
"It's really, 'How is Stephen going to come along?'" Towers said. "'Can we get Hill done?' It changes things. If something doesn't get done [with Hill], then Roberts probably becomes more your second baseman rather than your third baseman, and then our focus kind of moves more towards third than second. Hill's probably the key guy."
For overall baseball operations -- which includes, among other things, Major League payroll, operating expenses, the amateur Draft and international signings -- Towers said the team spent between $100-105 million in 2011 and will spend roughly the same amount in '12.
The question is, how much of those dollars will be allocated towards the Major League payroll, with their amateur signing bonuses expected to be quite a bit less than in 2011, when the D-backs had two of the first seven overall picks in the Draft?
"The great beauty of being here with Ken and Derrick is that it's kind of up to me on how I want to allocate the money," Towers said, referring to managing general partner Ken Kendrick and team president/CEO Derrick Hall. "A lot depends on the strength of the Draft, the depth of the Draft, how good things are internationally and how much we think we need to spend to be as good or better than we were last year."
The D-backs might bring back free-agents-to-be Jason Marquis, Lyle Overbay, Xavier Nady or John McDonald, but will not do so before the end of the exclusive negotiating window, which ends on the fifth day following the World Series.
The club holds mutual options with infielder Willie Bloomquist and catcher Henry Blanco and would like to have both players back, while it will all but certainly decline left-hander Zach Duke's $5.5 million option for next year and instead give him a $750,000 buyout.
Contract issues Free agents: RHP Jason Marquis; IF/OF Xavier Nady; SS John McDonald; 1B Lyle Overbay
Eligible for arbitration: RHP Micah Owings; INF Ryan Roberts; RHP Brad Ziegler; LHP Joe Saunders; C Miguel Montero; OF Gerardo Parra (Parra could qualify for arbitration as a Super Two, but is projected to fall just short of enough service time.)
Non-tender candidates: Owings, Saunders
Club options: 2B Aaron Hill, $8 million; LHP Zach Duke, $5.5 million ($750,000 buyout)
Mutual options: INF Willie Bloomquist, $1.1 million ($150,000 buyout); C Henry Blanco, $1.15 million ($250,000 buyout)
Areas of need Third base/second base: If they re-sign Hill, the D-backs will go looking for a third baseman. If Hill is re-signed, then Roberts stays at third and the D-backs could look to bolster their depth at shortstop.
Left-handed-hitting first baseman: With Paul Goldschmidt entrenched as the starter, the D-backs will look for a backup who hits left-handed. It is possible they could bring back Overbay to fill that role.
Left-handed relief: The D-backs were pleased with Rule 5 pick Joe Paterson, but the club would like to add another lefty to the bullpen. Arizona picked up Mike Zagurski from the Phillies in late September with the idea that he could be that guy, but don't be surprised to see the D-backs go hunting in the Rule 5 Draft again this year. They won't spend big money on this position.
It's still a moving target, but the D-backs project to spend roughly the same amount, or a little more than the $65 million they did in 2011. There are some players due raises in their contracts -- Chris Young ($2 million), Drew ($3.1 million), Justin Upton ($3.75 million) and J.J. Putz ($500,000) -- and arbitration should provide boosts to Saunders and Montero.
Steve Gilbert is a reporter for MLB.com. Follow him on Twitter @dbackswriter. This story was not subject to the approval of Major League Baseball or its clubs.