"It'll stick with you just a little bit longer," Bettis said. "You put your team in such a bad situation, right out the gate. The bullpen's got to cover 7 2/3 [innings]. That's not how you want to leave a game by any means.
"It's going to stick with me a little longer than it should. But at the same time, you've got to get ready and prepare for the next start."
Bettis walked leadoff man Gregor Blanco after seven pitches, and never found his strike zone. After a Chris Iannetta double -- which bounced out of the glove of center fielder Charlie Blackmon, who nearly made a dazzling, diving catch -- and a Jake Lamb walk, Paul Goldschmidt's bases-loaded single provided a 1-0 lead.
The only bright spot came when third baseman Nolan Arenado fielded J.D. Martinez's grounder to cut down a run at the plate.
Then, Brandon Drury walked to force in a run, A.J. Pollock doubled in three, and Bettis was gone.
Bettis, 28, who developed into a key pitcher last season, battled testicular cancer during the offseason and through much of the year, and didn't make his 2017 debut until Aug. 14. He went seven innings in each of his first two starts, and hadn't gone fewer than five until Thursday.
Throughout the year, Bettis' fastball has at times reached the 92-mph range of the past, but also has dipped into the 88-89 range. The velocity was mostly lower Thursday, but this time the location and the secondary pitches weren't sharp. His three walks were the most in any game this year.
"It's rare for Chad," Rockies manager Bud Black said. "You look at his walks per innings pitched, outstanding.
"[The walks] got him behind the 8-ball, and [the D-backs] are swinging well."
The Rockies hold a 2 1/2-game lead on the Brewers and Cardinals for the second National League Wild Card. Colorado is coming off a 6-2 road trip, but has rotation questions.
Righty Tyler Chatwood, who has battled high walks this season, is fully back in the rotation and will start Friday against the Padres to open a three-game homestand. Because rookie lefty Kyle Freeland has not pitched effectively for five starts (0-3, 5.73 ERA), second-year lefty Tyler Anderson will make his first start since suffering a knee injury on June 25 when he faces the Padres on Saturday.
Bettis' poor performance came a day after rookie righty German Marquez had his second straight short start, in Wednesday night's 8-2 loss to the D-backs. Righty Jon Gray, in his second full season, is 3-1 with a 2.25 ERA over his last four starts, and appears the most solid.
With the expanded roster, however, the Rockies can absorb some struggle. Lefty Chris Rusin, who threw 2 2/3 innings after Bettis left Thursday, has been dependable, and rookies Antonio Senzatela and Jeff Hoffman -- who made their marks as starters during the season -- are available out of the bullpen with September's expanded roster.
However, it's just as possible that Thursday was simply a blip for Bettis, who doesn't believe the rotation is in trouble.
"When all is said and done, it's one game," Bettis said. "We've got a couple weeks left in the season, and we've got to focus on that."