Rox fall to Nationals behind another rough start from Germán Márquez.

The Rockies had a prime opportunity. Down by two in the fifth, they had the bases loaded with one out, their best hitter was up to bat and a chance to erase the bad start from the pitcher who was supposed to be their top guy this season. But CJ Cron grounded into a double play, and just like that the chance was squandered.

So it goes for the Rockies, who can’t get anything to go their way lately. They fell to the Nationals 7-3 on Thursday, another winnable game gone astray. Colorado has now lost 13 of their last 17 games, including three out of four on this seven-game road trip.

“We were one hit away from taking the lead or potentially tying the game,” manager Bud Black said.

The game began with another rough outing from Germán Márquez. He was the player they thought was going to make a big leap this season, building on a season that included his first AllStar nod. That has not been the case.

Márquez gave up four of his five runs in the first inning on Thursday night as location issues continued to plague him. There were low-center fastballs sent to Nelson Cruz and Josh Bell for one run each, then one down the middle of the plate to Yadiel Hernandez for two.

Márquez faced the entire Nationals lineup in the first inning, needing 31 pitches to get out of it.

“I’ve been frustrated,” he said. “I want to go out there and pitch great games. Baseball is up and down. I have to keep going and going out there to pitch my games.”

For the second outing in a row, he was able to rebound from a bad inning by refocusing and finding a way to keep the ball down, but, in both instances, the damage had already been done. Márquez’s ERA is now 6.30, the second-highest among qualified starters in the majors.

“The first inning was rough,” Black said. “Behind the count and pitches in the middle against a group of hitters who are pretty good. ... after that he seemed to get the ball down a little better. Still didn’t have a great feel for the slider, but ended up making better located pitches.”

Márquez said that it’s not only the fastball, but that he also doesn’t have a feel for his slider or curveball right now. He’s using the curveball less than in years past — only 15 percent of the time compared to closer to 20 percent a year ago.

Off-speed pitches have been a battle for him over the past five games, he said, and it’s showing in his performance. Marquez has given up 22 earned runs in that stretch.

“When my fastball is good, everything is good. ... It’s confusing,” he said. “I don’t know what happened.”

The offense recorded eight hits but were only 1-for-9 with runners in scoring position. José Iglesias, Charlie Blackmon and Cron all had RBIs. Blackmon’s triple in the third was the 53rd of his career, tying Dexter Fowler for most in franchise history.

Injury notes

Kris Bryant (lower back strain) took a baby step forward on Friday, playing light catch on the field prior to the game. He returned last weekend from the same injury, but played only two games before he was placed back on the injured list (retroactive to May 23).

Antonio Senzatela (back strain) will make a rehab start on Friday with Triple-A Albuquerque. He’s expected to throw five innings or 75 pitches. If all goes well, he could make his next start back with the Rockies.

Robert Stephenson (illness) is expected to be activated on Friday. He was put into quarantine after having COVIDlike symptoms on Sunday, but he tested negative and was diagnosed with a stomach bug.