Purely based on runs scored, the Diamondbacks were among the best teams in the National League last year, trailing only the Colorado Rockies (for obvious reasons). By OPS, they were second, one point behind the Dodgers, and even adjusting for park, they were third by OPS+. This winter saw the departure of Ender Inciarte for Atlanta, in the deal which brought us starting pitcher Shelby Miller. That opens the door for Yasmany Tomas to become the everyday right fielder, a move which is perhaps more likely to hurt the team on defense than offensively, though the latter will depend on whether or not Tomas fixes the hole in his swing.
But there is still room for improvement, and it may be needed, not just to counter the loss of Inciarte - there's potential regression from Paul Goldschmidt (he's eventually got to find his ceiling, surely?) and A.J. Pollock. Earlier in the week, GM Dave Stewart said, "I wouldn’t mind adding a little more offense." The obvious spot at which the team can improve is second-base, where the Diamondbacks in 2015 got a line of .220/.266/.340, for a .605 OPS that was easily the worst in the league. That's likely why the team has already talked with the Reds this winter about a potential swap of Brandon Phillips for Aaron Hill.
However, that front seems to have fizzled out; the D-backs apparently are wary of taking on too much of Phillips 2017 salary, and there's also the question of his no-trade list to be overcome. It appears the Diamondbacks still have some money left to spend, so the free-agent market at the position remains another possibility. Howie Kendrick, who spent 2015 with the Dodgers, is one such possibility, having put up an OPS+ better than 100 over each of the past five seasons, and the team said they had been in touch with the 32-year-old. However, the cost may be too high, both in sheer cash and other assets.
Kendrick declined the qualifying offer made at the end of last season by Los Angeles, a one-year contract worth $15.8m, so he's clearly looking for, and expecting, more than that. Despite a solid 107 OPS+, it's worth noting he was deemed below average defensively, which slashed his overall value to 2.1 fWAR. STEAMER has him projected for 2.4 fWAR in 2016, but it's hard to imagine the team taking on his contract, while still also having the 33-year-old Aaron Hill on the books for 2016. That qualifying offer also means signing Kendrick would cost a draft pick, though with the team already having lost their 1st-rounder due to Greinke, that matters less to AZ than other candidates.
Another possibility would be a cheaper alternative, who can bat left-handed and act as a platoon option with Aaron Hill and/or Chris Owings. That would particularly be the case for Hill; in his career to date, Owings actually has reverse splits, with a better OPS against right-handed pitchers (.654) than lefties (.588), though with barely 200 of the latter, were still in small sample size territory. If the team was looking for a left-handed or switch candidate, who might be available? There were actually a slew of former D-backs that fit those criteria, though a number are now off the market: Stephen Drew, Cliff Pennington and Emilio Bonifacio all signed deals this winter. Those remaining are:
Alberto Callaspo - age 32, 2015 salary $3m
Another former Diamondback, you wouldn't be getting very much offense here, having posted OPS+'s of 67 and 68 the past two seasons. Additionally, while a switch-hitter, he bats better from the right-hand side than the left, so wouldn't be much of a platoon.
Jonathan Herrera - age 31, 2015 salary $900k
An even worse hitter than Callaspo, most clearly shown in a .658 OPS put up over five years with the Colorado Rockies. He didn't even reach .600 in the past two years, with the Red Sox and Cubs. Has hit slightly better as a LHB, but not enough to whelm of any kind, least of all over-.
Maicer Izturis - age 35, 2015 salary $3m
After just 11 games in 2014, he missed the entire 2015 season with a groin strain, followed by a shoulder injury during a rehab assignment. With a career .710 OPS as a left-hander, there's worse out there (see above). But age and health are huge question-marks. ST invite at best.
Kelly Johnson - age 33, 2015 salary $1.5m
There'd be something fitting about bringing Johnson back, considering we traded him to Toronto to get Hill. The sole "true" LHB, Kelly was solid (108 OPS+) with the Mets & Braves last year, thanks to heavy platoonage (all 78 starts came vs. RHP) and seems easily the remaining best free-agent candidate for a similar role on the 2016 Diamondbacks.
Any additional signing would create an infield roster crunch. Assuming five spots on the bench, and two of those used by a catcher and outfielder, that leaves three at most for infielders. We already have Hill/Owings, Phil Gosselin and Brandon Drury as options, and that's another reason why signing a left-handed bat would make sense, because all of them are right-handers. Drury would seem the odd man out in the event of any further new arrivals, not least because of his young age (he only turned 23 in August).
If no free-agent is signed, the team can either stand pat, and keep their fingers crossed Owings figures things out (he's 24, so it's not impossible), or figure out a trade. Right now, the public indications appear to the former, Stewart saying "It’s been quiet on our front. We haven’t really had very many calls and we definitely have not reached out to anybody to do anything. We’re just kind in wait mode and see where we are." So, translating from the Stewartish, there's clearly a blockbuster trade coming, in 3... 2... 1...!