LOS ANGELES -- With just 12 days remaining in the regular season and the Rockies in the heart of a pennant race, the team has elected to shuffle its starting rotation heading into Friday's series at Arizona after a discouraging performance from Jon Gray in his last start.
Colorado will skip Gray's next start, which was slated to be Sunday for the finale of the series against the D-backs. Because of a scheduled off-day on Thursday, the Rockies plan to start Kyle Freeland on normal rest instead.
The Rockies entered Wednesday's finale of a three-game series against the Dodgers Wednesday 1 game behind St. Louis for the second National Leage Wild Card spot and 1 1/2 games behind Los Angeles for first place in the NL West.
Gray struggled in his last start Monday against the Dodgers, with the Rockies losing, 8-2. He was tagged for six runs and seven hits over just two-plus innings. It was Gray's shortest start of the season, and his third straight start in which he couldn't last more than four innings pitched.
Gray blamed mechanical issues for his poor performance.
"I just got so mechanical out there, something I promised myself I wouldn't do," he said Monday. "That's where it took me. I was really not happy with that.
"The thing for me is not thinking about the mechanical stuff when I'm competing," he added. "That can get in the way. It got in the way a lot tonight and I've had it happen to me too many times already. I'm sick of it right now."
After a brief Triple-A stint in June, Gray notched nine straight starts in which he went five innings or more. In seven of those starts, he allowed three runs or less. But the mechanical insufficiencies from earlier in the season have resurfaced.
"It's very similar from the time we sent him down to Albuquerque, where there was command issues, there was a few delivery issues," manager Bud Black said. "The delivery has cleaned up a little, so now it's a matter of what all pitchers go through. ... The last three starts for Jon have been not Jon-like."
The Rockies plan to start German Marquez, Antonio Senzatela and Freeland against Arizona. Marquez and Senzatela will pitch on an extra day of rest. They'll face off against Zack Godley, Zack Greinke and Patrick Corbin, respectively.
Story remains day to day
Trevor Story remains day to day with elbow soreness and hasn't resumed baseball activity since departing Monday's game.
He will head to Colorado's Spring Training facility in Scottsdale, Ariz., during the off-day on Thursday before rejoining the club on Friday in Phoenix. The main priorities are ice and treatment, but there is a chance he resumes some baseball activities before Friday.
An MRI revealed Wednesday no structural damage for Story, who tweaked his elbow making a throw on a diving play on Monday. He left the game in the fourth inning, when he extended hard on a swing. 

"It's obviously always scary when you're talking about an elbow, but getting those results from the MRI was huge," Story said. "In my gut I felt like it wasn't anything serious. It felt better yesterday and continues to feel better."