Rockies right-hander Jon Gray knows that to perfect his changeup, he has to throw it. But Friday night was not what he had in mind.

The problem was that his fastball was a magnet for the Dodgers’ bats, who lead the Majors in runs scored. His best secondary pitch, his slider, was so ineffective he barely used it. And, well, being limited to his third pitch, Gray wasn’t nearly good enough in the 5-1 loss -- the Rockies’ 10th defeat in their last 12 games.

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“It’s tough to explain,” said Gray, searching for words the way he searched for pitches, and even exasperatedly raising his hands trying to find the right description. “You don’t have your bread and butter and you can’t locate. You don’t really know what’s going on. That’s a tough day.”

It was the Rockies’ 21st loss in their last 25 games against the Dodgers, and 14th in the last 15 at Dodger Stadium. After an 11-3 start, Colorado is at .500, 13-13. After going seven strong innings while winning his last start, Gray lasted just 3 2/3 innings and gave up four runs on seven hits.

“I can’t describe how frustrating it is, especially with how important the game was,” Gray said.

It was the second time in the last three starts that Gray didn’t make five innings. But Coors Field played a role in his giving up eight runs and 11 hits in 3 1/3 against the D-backs on Aug. 10. This one, Gray simply had nothing, and his pitch distribution showed it.

Here were the numbers coming into Friday:

• Four-seam fastball: 41.3 percent
• Slider: 30.2
• Changeup: 12.3
• Curveball: 9.7
• Sinker: 6.6

This is what the Dodgers’ lineup feasted on Friday:

• Changeup: 32 percent
• Four-seam fastball: 28
• Slider: 18
• Sinker: 15
• Curveball: 7

It went wrong from the start.

In the first, leadoff man Joc Pederson fouled off four straight fastballs to run his at-bat to an eighth pitch. Unable to induce a swing and miss, Gray finally tried a slider. Pederson smoked it 104.5 mph for a double. Two batters later, Gray had some success with the changeup, but went to a fastball that Justin Turner knocked for a single. The next batter, Cody Bellinger, by then realizing the changeup was all Gray had, banged an RBI double at 102.6 mph for a 1-0 lead.

Gray escaped with no further scoring, and skated through hard contact with the right pitch here and there. The third inning featured a fine defensive backhand and throw from second baseman Ryan McMahon on Justin Turner’s grounder to the middle, and another grounder for the Rockies’ Majors-leading 31st double play.

But after Matt Beaty’s RBI single and Cory Seager’s two-run double in the fourth, manager Bud Black could not give Gray any more time.

“The velocity was there, the command wasn’t,” Black said. “It looked as though Jon couldn’t get anything going. He made some pitches, we made some plays for him. I thought our defense tonight was outstanding.

“There are times when a pitcher can bob and weave and hang in there through five or six outings. But it didn’t happen tonight for Jon.”

The Rockies scored their only run in the sixth inning, but had a chance to bail Gray out when Charlie Blackmon and then Nolan Arenado came up to bat down by three with two men on. But Blackmon struck out and Arenado had a potential run-scoring hit taken away on a nice running grab by Joc Pederson in right field, quashing the rally.

Over a career that has seen Gray become the first pitcher in club history to earn double figures in wins for four straight seasons (the last four), he has struggled to 5-plus ERAs in the first two months before putting up better numbers and at times going on rolls. Of course, this shortened season doesn’t afford him the ability to do that.

“You'd like to think that it's in there every time, that a pitcher can throw really well,” Black said. “It just comes down to momentum.

“Jon hasn't found that yet.”