If the team wants to keep the orientation as close to that planned as possible, and avoid disrupting any other positions, the simplest thing to do is replace Adam Eaton with Gerardo Parra in center-field, leaving Jason Kubel in left and Cody Ross in right. However, there are other possibilities. Cody Ross could play center, the position which he apparently told Kevin Towers he feels most comfortable. We could then have Parra operating in right, where he does have some experience - 13 starts there last year - with Kubel as usual in left.
However, there is a pretty big question-mark over Cody Ross's fitness right now, and it's by no means certain that he will be available by Opening Day either. If that's the case, then we are probably looking at something like the line-up which started the game last night in Goodyear, the first of the post-Spanky period. That Diamondbacks card had Kubel in left, Parra in right, and A.J. Pollock covering center field. 14 of Pollock's 19 starts last year were in CF; in the minors with Reno last year he was slightly more "roamy", though still with the majority of his work coming in that position.
Another possibility would be to put the versatility of Martin Prado to use. While signed as a third-baseman, and that's been the spot he has occupied almost all of spring, that wasn't the case towards the end of his time with Atlanta. In both 2011 and 2012, he was largely a left-fielder, making a total of over two hundred starts there, compared to only 54 at third-base. And let's not forget Eric Hinske, who has 130-odd starts at both of the corner outfield positions, though over the past three years with Atlanta, it has been much more LF (79 starts) than RF (17). And then there's always Willie Bloomquist. Trust me: there's always Willie Bloomquist...
The problem with those options would be that they are really only credible left-fielders, so are not strictly a replacement for Eaton, and it's not as if the incumbent, Kubel, can slide over. He could conceivably operate in right-field, as he did with the Twins - 79 starts there in 2010 - but the metrics don't exactly like him there. His UZR/150 in right is -16.1, which is getting toward the level of a traffic-cone in Sedona Red. Additionally, using Prado would fill the hole simply by creating another, at third-base. Sure, Eric Chavez could fill in for a while, but told Nick Piecoro, "He's only capable of playing 3-4 days in a row at this point in his career."
Except in the unlikely event of one of the infielders moving to the outfield regularly, Gerardo Parra will likely be playing every day, and it seems that Pollock gets to move up the depth-chart and take over as fourth outfielder. As noted, he has decent positional flexibility, and has seen plenty of playing time so far. Indeed, going into last night's game, only Eaton had more Cactus League ABs than Pollock, and that probably won't last beyond the weekend. His numbers there have been okay; nothing spectacular, but better than the spring stats for either of the two other possible contenders, Tony Campana or Alfredo Marte. Still, the quote above now seems eerily prophetic...
If Cody Ross is also forced to start the season on the DL, then it's likely Campana will get the call to become the reserve outfielder, though he's out right now, after the stitches in his hand re-opened. I'm not sure how much playing time he will get - at least, in terms of hitting, because his on-base skills are about at the traffic-cone level as well. However, no-one argues doubts his great wheels, and in the ninth inning of a one-run game, someone who can pinch-run and turn a walk into, effectively, a double or even a triple, is a valuable asset. It'd certainly be fun to watch, and used correctly, he could be a decent asset to the team. The important phrase there is "used correctly"...
While Kirk Gibson would never be so forward as to say it, instead growling, "That's for him to go earn, though. I'm not going to give that to him today," there seems little doubt that Eaton would have been the Diamondbacks' leadoff hitter. And he'd have been a legitimate one, possessing both speed and on-base ability, in a way that we haven't seen in Arizona for quite some time. There's no-one who has the same combination of skills, so it's not clear what will happen there.
Last year, we had Bloomquist hitting first in almost one-third of games, with Parra pulling duty in close to a quarter more. Of the new arrivals, Prado hit second nearly exclusively for the Braves last year, and Cody Ross, even if fit, is not an option at all. One imagines it will probably be mostly Parra, with Bloomquist likely getting the nod from Gibson whenever he starts. However, given the two have been tussling for the title, King of the TOOTBLANS, for the past couple of years, seeing them trying to kick-start the offense is not something which fills me with optimism.