CINCINNATI -- For his fifth big league start on Saturday, Reds rookie Luis Castillo was opposing one of the game's best pitchers in Nationals ace Max Scherzer. Yet it was Castillo who didn't allow any hits for the first three innings.
Castillo wasn't able to sustain that success in the fourth inning, the only inning where he was touched up in a 10-7 Reds loss. In six innings, the 24-year-old prospect allowed three earned runs and three hits with four walks and six strikeouts while doing nothing to lower manager Bryan Price's optimism about his pitching future.
"Tough loss for him, to go six innings of three-run ball, but another step in the right direction with this kid," Price said. "I think we're all excited every time he takes the mound right now."
Castillo is 1-2 with a 3.41 ERA in 29 innings with 25 hits, 14 walks and 36 strikeouts. Once again according to Statcast™, his velocity was perky as he averaged 97.9 mph with his four-seam fastball. He struck out Bryce Harper to end the first inning with 98-mph heat.
"Today I was attacking the zone," Castillo said via translator Julio Morillo. "I was trying to get ahead of the count. I just need to practice with my breaking-ball pitches and being more consistent with those pitches. I felt really good today."
One area where Castillo didn't fare well was with two outs. Of his seven batters to reach safely, six had two outs. Harper's fourth-inning, one-out single -- Washington's first hit of the game -- was the exception but it opened the door to trouble.
"Sometimes when you have two quick outs, you think the job is done and the game goes faster," Castillo said. "After that, you need to pick your tempo up. You have to make your pitches to make the outs."
Daniel Murphy drove a first-pitch fastball to the wall in left-center field for a RBI double. The next batter, Anthony Rendon, was in a 3-0 count before Castillo battled back to 3-2 with two fastballs for strikes.

Castillo attempted to get a third-straight fastball past Rendon, who attacked it for a home run to left field and a 3-0 Nationals lead. Against Scherzer, that makes it tougher to come back.
"I wanted to just challenge him," Castillo said. "I didn't want to walk him. A 3-0 count, everything that you throw had to be in the zone. I made a mistake, and he's a really good hitter. You can't make a mistake with him."
Price would have liked to have seen better pitch selection in that situation.
"One of the things he had done earlier in the game is he had been able to lock up a couple hitters on 3-2 breaking balls," Price said. "That's not to second-guess, because that's exactly what it sounds like, but I think he had done that to the point where they had to respect the breaking ball on 3-2. But Rendon was right on the heater and didn't miss it."