DENVER -- It was a tough ending for the D-backs on Saturday night, as Elias Díaz cranked a three-run homer with two outs in the bottom of the ninth inning to propel the Rockies to their MLB-high 12th walk-off win of the season, this one by a 5-2 margin.

But wins and losses stopped defining this D-backs season a while ago, and these final six weeks are about figuring out which young players they can build around. It's also important for them to get key pieces, like right-hander Zac Gallen, to finish the season strong as a springboard for 2022.

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By that measure, Saturday was a success. Gallen tossed seven scoreless innings, allowing only three hits and one walk and striking out nine in a dominant outing.

Gallen tweaked his mechanics a bit after allowing nine runs in 11 innings over his previous two starts. He looked closely at video of himself from when he was having success in the second half of 2019, as well as last year and earlier this season before his second stint on the injured list.

What Gallen saw was that his front shoulder was staying too closed, which made it hard for him to land his breaking ball the way he needed to.

"Breaking balls really didn't have a chance to stay in the zone long enough for strikes," Gallen said. "Either for called strikes or swings. I think that's pretty much been the biggest thing, and that was the adjustment today."

This was Gallen's third career start at Coors Field, and he learned right from his first outing here that there is definitely a difference pitching at a mile above sea level. Because his ball doesn't move the same at this altitude, he has to adjust his eye level and target a bit. It can take some time to do that, so surviving the first inning is the key.

The Rockies loaded the bases against Gallen with two outs in the first, but he got out of it unscathed and allowed only one more hit -- a third-inning single by Charlie Blackmon -- the rest of his outing.

"The first was a little shaky," Gallen said. "There's always an adjustment period coming here, the ball acts a little bit different, your body feels a little bit different."

Knowing that was important, because it kept Gallen from panicking early.

"I remember the first time I was here, I just really didn't know what to expect," Gallen said. "That first game was definitely an adjustment period back in 2019. And last year kind of was the same thing, where coming in I wasn't really sure how everything was going to go.

"And then as the game went on, I got into a rhythm and kind of was like, 'OK, that's where everything needs to be.' So it's kind of good to just have that in the back of my mind, that you've got to switch your sights a little bit when you come here."

Gallen's pitch count was at 96 at the end of the seventh, and given the fact that he's been on the IL twice this year, D-backs manager Torey Lovullo decided not to send him back out for the eighth.

"I think in another place in time, I would have explored it," Lovullo said. "Given everything that he's been through this year with a couple stints on the IL, just the battle that he's been showing us to stay healthy and get back on the field, I just didn't want to put him in that situation. I just felt like the risk outweighed the reward."