WASHINGTON -- At the beginning of May, Rockies starter Germán Márquez endured a seven-run blowup outing against the Nationals that left the right-hander searching for answers.

Flash forward to Thursday night at Nationals Park, and Márquez is hoping all of May was a mirage after bookending one of the least effective months of his career with another disappointing outing.

Márquez’s continuing struggles factored heavily into Colorado’s 7-3 loss, as he watched five earned runs further balloon his ERA to 6.30 -- the second-highest mark among qualified Major League starters.

It was the sixth start this season that Márquez allowed at least four earned runs, the most by any starter in MLB. Three of those came this May, when Márquez coughed up 23 earned runs in 29 innings across five starts.

“I’m going to go out there and pitch great games, but baseball is always up and down,” Márquez said. “I have to keep going.”

The result is a massive regression for the 2021 All-Star, who appeared to be emerging as one of the National League’s most dependable starters after a strong 2020 season and an excellent first half last season. But he’s morphed into one of MLB’s least effective starters since, pitching to a 6.20 ERA in his past 22 starts. 

Márquez's ERA is two runs higher -- 7.80 vs. 5.80 -- on the road, away from the thin air of Coors Field, in that span.

“It’s frustrating, but I need to keep going,” Márquez said. “I’m going to go out there and pitch great games, but baseball is always up and down. I have to keep going.”

The Rockies hope they witnessed signs of a turnaround in the series opener against the Nats, when Márquez held Washington to one run over five efficient innings after serving up four runs during a 31-pitch first.

Six of the Nationals’ first seven hitters reached in the first, as Washington capitalized with consecutive run-scoring hits from Nelson Cruz, Josh Bell and Yadiel Hernandez for a 4-0 lead. The hole was too much for Colorado to claw out of against Patrick Corbin and three relievers, despite Charlie Blackmon’s franchise-record-tying RBI triple in the third. Blackmon matched Dexter Fowler with his 53rd career three-bagger.

“The first inning was rough,” manager Bud Black said. “It looked like the pitches were in the middle of the plate. [Márquez] was behind in the count and pitches were in the middle against a group of hitters who are pretty good. That game could’ve went the other way for him, but he reeled it in.”

Still, Márquez was at a loss trying to explain his struggles in the postgame clubhouse, citing mechanical issues, lack of feel for his secondary pitches and shaky fastball command as underlying causes that seem to be compounding.

Without a feel for his slider or knuckle curve or the ability to locate his fastball early, Nationals hitters were able to sit on Márquez’s heaters as he threw 62 of them -- 60 percent of his pitches -- far exceeding his season average. He elicited swings and misses on only two.

Opposing hitters entered play batting .379 and .452 against Márquez’s four-seam fastball and sinker, respectively, this year. And while he’s found better results with the slider and curve, his curveball usage is down this year and his changeup has been a non-factor.

“It’s confusing -- I don’t know what’s happening,” Márquez said. “My breaking ball hasn’t been there. When my fastball is good, everything is good. I’ve been struggling a little bit with my breaking ball.”

The Rockies have lost six of Marquez’s past seven starts, and 13 of 17 overall.

“I think he’s still very confident in his ability,” Black said. “He has a lot of pride. I think he expects to throw a good game every time out there. I think his confidence level is high. This guy was an All-Star, and came into the season wanting to prove that.

“He’s made some pitches and innings over the course of this that have really hurt him. The first inning tonight was a back-breaker.”