Ultimately, they came up short, but their 79-83 record was a 15-game improvement over 2014 and it left them excited about taking yet another step in 2016.
"Obviously the goal is to play into October, which we didn't make, but next year that stays our goal," D-backs manager Chip Hale said after the season ended. "I thought the process was great. I've said it all year: I thought our guys were prepared. They brought it. So I think it was a success in that way."
Just how strongly the D-backs believed in their ability to win in 2016 would become apparent when they shocked the baseball world in early December by signing free-agent right-hander Zack Greinke to a six-year, $206.5 million contract, then traded for right-hander Shelby Miller.
Here's a look at some of the key storylines from 2015:
1. The new regime
Tony La Russa was hired as chief baseball officer during the 2014 season, and he wound up dismissing both general manager Kevin Towers and manager Kirk Gibson and bringing in Dave Stewart as GM and Hale as manager.
The trio, along with senior vice president of baseball operations De Jon Watson, worked seamlessly together during 2015, with La Russa acting as a sounding board for Hale in his first year as a big league manager, but also staying far enough in the background to make sure the team knew that Hale was in charge.
2. Flashing the leather
The D-backs were baseball's best defensive team when measured with the advanced metric Defensive Runs Saved.
Their defensive prowess was one of the reasons Miller was so excited to move from the Braves to the D-backs.
"They're so defensively sound and have a lot of guys that make plays and lay out," Miller said. "A lot of exciting players to watch."
3. Playing the game hard
La Russa, Stewart and Hale all said before the season started that regardless of the record, you could count on the fact that the D-backs would play the game the right way. In other words, they were going to play hard every day, take the extra base when possible, and execute the fundamentals.
For the most part, they did just that, and it didn't go unnoticed by a certain someone who was sitting in the visitor's dugout when the Dodgers came to town in early July.
"The Dodgers were playing Arizona, and I just was watching all their position players running around making all these great catches, taking extra bases like crazy against us," Greinke said. "You look at the leaderboard and they have the best offense in the game, scored the most runs. I was like, 'Dang, that's a pretty impressive group of guys they got over there.' I just realized it then."
4. Gold standard plus Pollock
For the second time in three years, Goldschmidt finished second in the NL Most Valuable Player Award voting. In 2013, he was the runner-up to unanimous selection Andrew McCutchen of the Pirates, and last year it was the Nationals' Bryce Harper who captured every first-place vote.
Goldschmidt was voted to start the All-Star Game for the second straight season, the first time a D-backs position player had ever been elected to start multiple games. In the process, he set career highs in batting average (.321), on-base percentage (.435), slugging percentage (.570), stolen bases (21) and walks (118).
Pollock, meanwhile, had a breakout season by putting up a career-best on-base-plus-slugging mark of .865 while being voted on the player's ballot to his first All-Star Game.
5. Big-time upgrades
When the season ended, La Russa and Stewart said their biggest priority was improving the starting rotation.
The D-backs did just that on Dec. 4, when they agreed to terms with Greinke on a deal that caught the baseball world off-guard.
Greinke had been down to deciding between the Dodgers and Giants and admitted later that he was literally minutes away from signing with a team (believed to be the Dodgers) before the D-backs reached his agent to say they had a proposal to make.
Less than six hours after that initial contact, a deal was done and the D-backs followed that up just days later by landing Miller from the Braves in a deal that cost them Inciarte, Minor League pitcher Aaron Blair and last year's first-overall Draft pick, shortstop Dansby Swanson.
"Our ownership stepped up in allowing us to get Zack Greinke," Stewart said in announcing the Miller trade. "It puts us in a position to do better as a team. But we weren't complete. We needed an additional piece to our rotation."
They got that in Miller, and it made for a happy holiday season in Arizona, with the D-backs anxiously awaiting 2016.