PHOENIX -- The D-backs didn’t go into the offseason thinking they were going to sign free-agent left-hander Madison Bumgarner.

Yet, there was general manager Mike Hazen on Tuesday at a news conference explaining how the D-backs were able to reel in Bumgarner for five years and $85 million.

Here are some questions and answers about the Bumgarner signing and what it might mean for the future:

Why Bumgarner?

“When we traded Zack [Greinke] last year, we knew we were missing something at the top of our rotation,” Hazen said. “We knew, over the next couple years, finding somebody to anchor our rotation was going to be a need.”

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Outside of Robbie Ray and Mike Leake, the rest of the Arizona rotation is short on experience. Luke Weaver, Zac Gallen, Merrill Kelly, Taylor Clarke, Alex Young and others competing for spots will benefit, the D-backs believe, from watching how Bumgarner goes about his business.

What about Ray?

Ray will be a free agent after 2020, and even before Bumgarner was signed there was speculation that the team could look to move Ray before he reaches free agency.

It still seems like the D-backs will seriously explore trading Ray, either to fill one of their two open outfield spots or to acquire prospects they could flip for an outfielder (Seattle’s Mitch Haniger, perhaps).

Hazen understands why that speculation exists.

“It makes a ton of sense,” he said. “That is a linear way of looking at the roster construction. That is certainly a path. That was not our intention with this. We like the way our starting rotation sets up. We know we still have needs on the team that we need to address somehow and someway. You don’t always know, even today, what that way may be.”

How does this impact the payroll?

Bumgarner agreed to defer $15 million of his contract so he will be paid just $6 million in 2020, which leaves the D-backs with almost $20 million left to spend this offseason.

That means they don’t have to trade Ray if they believe they can adequately address their outfield needs some other way.

And if there’s one thing that Hazen and his baseball operations staff have shown in his three years, it’s that they are creative. So while they may indeed trade Ray, they also may do something completely unexpected.

“We just have to be somewhat flexible in how we construct our roster,” Hazen said. “I would love to be able to make declarative statements about how things are going to [go]. ‘Well, now that we’ve done A, we want to do B.’ That would be a very simple way to live. Unfortunately, I just don’t feel like we’re ever in that spot where we can afford to do that. We always have to remain flexible in how we’re trying to construct the roster.”

What do they make of Bumgarner’s numbers declining in recent years?

“Look, yeah, we’ve parsed through a lot of the numbers,” Hazen said. “It is what it is. I get it. I think what we saw this year was we thought we saw a really good starting pitcher.”

The D-backs think there are some subtle changes that they could make that would help Bumgarner.

Remember, the D-backs recently hired Matt Herges as their pitching coach. Herges worked closely with Bumgarner for two seasons as the Giants' bullpen coach.

They also have pitching strategist Dan Haren, who has been hugely successful in helping design game plans for pitchers over the past few seasons.

“I think the things we’re probably talking about are subtleties more than anything else, but those subtleties sometimes make a big difference,” Hazen said.