Chase Anderson was long gone from Sunday’s game, having recorded only 11 outs, when two potential back-of-the-rotation options for the Phillies materialized on the mound in Colorado.

One, Spencer Howard, was already wearing red and gray.

The other: Rockies starter Jon Gray.

Let’s get back to that momentarily. For now, after Anderson got KO’d in the fourth inning of a 12-2 shellacking by the Rockies, after the Phillies slipped back below .500 at 10-11, the pertinent number is this: In games not started by Aaron Nola, Zack Wheeler, and Zach Eflin, the Phillies have a 2-6 record.

“It is frustrating because I signed here because I wanted to win,” said Anderson, who has worked only 16 2/3 innings in four starts. “I know I can pitch at this level and continue to for a long time. It just comes down to execution and making pitches and trying to get deeper in ballgames.”

Anderson did neither against the Rockies because of two cardinal mistakes in the fateful fourth inning. With two out and the Phillies leading by one run, he walked the No. 8 hitter (Dom Nunez) on a curveball in the dirt, then left a cutter up to the pitcher (Gray) for a game-tying RBI single.

The inning unraveled from there. Anderson allowed another RBI single and a walk to load the bases. He was lifted for David Hale, who promptly hung a breaking ball that Trevor Story launched for a grand slam to open a 7-2 Rockies lead and leave Anderson with at least one regret.

“I get out of there with one [run] with getting the pitcher out,” Anderson said. “That’s probably the one that hurts the most. The walk, I don’t really mind right there, just knowing the pitcher’s on deck.”

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Success for the Phillies is predicated on two basic things: quality starts in 60% of their games from Nola, Wheeler, and Eflin, and their best players on a top-heavy roster being the best players on the field most of the time.

They won Saturday night behind Nola and two homers from Rhys Hoskins. And Bryce Harper supplied a 2-0 lead Sunday with homers in his first two at-bats against Gray and a strong throw to cut down C.J. Cron at the plate in the second inning.

But the plan comes apart when Anderson and fellow back-of-the-rotation starters Matt Moore and Vince Velasquez don’t at least keep the Phillies close. In eight starts among them, they have combined for a 7.39 ERA and logged a total of 31 2/3 innings, a bullpen-draining average of less than four innings per start. That isn’t sustainable.

“We need more out of them,” Girardi said. “And I think they’re more than capable of giving us more.”

Said Harper: “You want them to give you the best chance to win each day that they go out there, any of our pitching. Our offense definitely hasn’t been there for a couple days now. Us as an offense, we need to be better, but also starting pitching and defense wins ballgames. We just need to be better all around as a team.”

Internally, the Phillies lack options to replace struggling starters. Unless, of course, they unleash Howard.

The Phillies want their top pitching prospect to work meaningful innings this year. But after a shoulder problem curtailed his workload in back-to-back seasons, they don’t know how many he will be able to provide or whether they will come in the bullpen or the rotation.

Some quick math: If Howard entered the rotation now and gave the Phillies four innings per start for 28 starts in a piggyback situation with, say, Anderson or Velasquez, he would rack up 112 innings, a relatively reasonable expectation for him this season.

“We have a number in mind, and I don’t think you change that,” manager Joe Girardi said. “I think it’s important that we get him to the number and we do it the right way.”

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Regardless, mopping up for Anderson and Hale probably isn’t the best use of those innings.

“I would’ve used him in a close game. The game just got away from us,” Girardi said. “I’m not going to use [Connor] Brogdon in that situation. I wasn’t going to use [Brandon] Kintzler or [Sam] Coonrod. To get through the game, I thought I had a couple guys that could give me multiple innings, and that’s what I did.”

Gray, meanwhile, had little trouble with the Phillies save Harper. The tall right-hander, a former first-round pick, has a 2.54 ERA in four starts after struggling last season. But the Rockies -- even after taking two of three games from the Phillies -- have the worst record in the National League.

If you’re betting on a pitcher to be dealt before the July 31 trade deadline, Gray is a solid candidate, especially considering he’s making only $6 million and is eligible for free agency at season’s end. As short-term rentals go, he fits the profile.

“He threw a good ballgame,” Girardi said. “It’s interesting: He’s actually pitched better here than on the road, which you don’t usually see. He’s one of those guys that you better get to him early or he’ll settle in, and that’s exactly what he did.”

The Phillies are still waiting for their fourth and fifth starters to settle in. Until then, they have to consider every potential option.