And his record stands at 1-7 and the Reds have lost nine of his 10 starts.
Any thought of pulling Castillo from the rotation or skipping a turn or two were quickly scotched by manager David Bell.
“We are just going to continue to help him through it,” said Bell. “His next start is Saturday in Chicago and he’ll be out there. He is going to have a great week of work and continue to do everything he can and we’re going to be here for him to help him through this.
“We’ll make any adjustments he needs to make,” Bell added. “He knows better than anyone that he can be better and is going to be better.”
Castillo put his team in a quick 5-0 hole in the first three innings. And as has happened so many times this season, the first inning was rough and tumble.
He gave up three runs after getting two outs. Kolten Wong opened the game with a single, but Castillo retired the next two.
But he gave up a single to Avisail Garcia and walked Daniel Vogelbach to load the bases.
Then he also walked Travis Shaw, who was 1 for 25 at the time, forcing in a run. Willy Adames singled to center for two runs.
And the Reds were down, 3-0, before they swung at their first pitch.
It became 5-0 in the third when Castillo walked Christian Yelich, 0 for 11 since coming off the injured list, and Garcia homered.
“It was just another bad day for us,” said Castillo. “We’ve had plenty of these this year. Just another bad day, what more can I say.”
Through all his travails Castillo has tried to remain on the upbeat and not let setbacks creep into his confidence.
“Every bad moment, every time we have a bad time, we know it is going to end eventually,” he said. “I can’t think that I’m going to be frustrated all the time. It is not going to be good for me. I’m out there enjoying the game as much as I can. I’m trying to have a good time out there. I always have a positive mentality, even after every pitch.”
For four innings, the Reds had only one hit against Milwaukee starter Freddy Peralta.
And that one hit? What else? A Jesse Winker home run. His third-inning rip, a 456-foot drive off the smoke stacks in right center, was his fifth homer in the three-game series.
The last time a Cincinnati Reds player hit five homers in three games was in 1996, performed by Willie Greene against the Chicago Cubs.
The Reds crawled within 5-2 in the fifth. Pinch-hitter Shogo Akiyama doubled off the left field wall and Nick Castellanos nearly knocked down the wall with a double to left for a run.
With two outs, Peralta walked Tyler Stephenson and was removed, one out shy of qualifying for his fifth victory this season.
Brad Boxberger, a Reds’ No. 1 draft pick, replaced Peralta and hit Tucker Barnhart with a pitch. That filled the bases — the potential tying runs on base — but Eugenio Suarez struck out, leaving it at 5-2.
Earlier, the Reds filled the bases with two outs in the third before Barnhart grounded out.
Michael Feliz and Sean Doolittle were called upon to keep it at 5-2 and failed. Feliz gave up a walk and a single. Left-hander Doolittle was brought in to face the left-handed Wong. He tripled up the right center gap to make it 7-2 and Yelich snapped his 0 for 13 skid with a run-scoring single.
Yelich struck even harder in the ninth with a solo home run off Reds relief pitcher Brad Brach.
The one team constant, the Winker-Castellanos duo, struck in the ninth, just for fun, Winker singled and Castellanos clubbed his 11th home run.
Those two had five of the team’s seven hits and drove in all four runs.
Reds at Nationals, 7:05 p.m., Bally Sports Ohio, 700, 1410