MILWAUKEE -- It’s not often this season when Reds starting pitcher Luis Castillo endures poor starts, yet it has happened twice at Miller Park. But this ace has his own ace up his sleeve only a phone call away.

Castillo had an off day as he threw 96 pitches over only 3 2/3 innings Saturday while the Reds saw their season-high six game win streak end with a 6-5 defeat to the Brewers. He allowed six runs -- four earned -- with five hits, five walks and six strikeouts. Of concern is that the right-hander has walked 11 batters in his past two starts, including a career-high six vs. Houston on Monday.

He’s issued 17 walks over his last four starts, totaling 21 2/3 innings, and 49 so far this season after walking 49 in all of 2018 (169 2/3 innings).

• Box score

“I don’t know what’s going on, to be honest. I’ve been talking to Pedro Martinez a lot and he’s been helping me a lot with that. Just giving me a lot of advice,” said Castillo through translator Julio Morillo.

Yes, that Pedro Martinez -- the Hall of Fame pitcher and former Red Sox and Expos star and current MLB Network analyst.

“Yeah, I talked to him back in the Dominican Republic. Now I have his cell phone, so I can contact him any time I want,” Castillo said.

For the third consecutive game, Cincinnati opened a 3-0 first-inning lead after Derek Dietrich hit a two-out RBI triple against Jhoulys Chacin and Yasiel Puig immediately followed with a first-pitch two-run home run to left field.

A stunning defensive play stopped the momentum when José Iglesias grounded up the middle to second baseman Mike Moustakas, who made a no-look flip from his glove to shortstop Orlando Arcia. He spun and threw to first base. Although the initial call was safe, the Brewers challenged and won on review.

“We were trading blows yesterday, too, so you just have to keep scoring,” said Dietrich, who set an MLB record with his sixth HBP in the series. “We still put runs across. We could have cleaned up a few things on [defense] and they hit some balls well today. Nothing alarming or concerning. We’ll just get back out there tomorrow and hopefully score two, three more in the first.”

It took little time for the Brewers to get the runs back against Castillo. Switch-hitter Yasmani Grandal led off for the first time in his career and promptly hit a 1-0 fastball to right field for a homer in the bottom of the first.

“I think the secondary pitches, my slider and changeup were really good. Fastball command wasn’t; I was trying to throw in to lefties and the ball was running back into the middle of the plate,” Castillo said. “I have to give them credit too, because they were laying off really good secondary stuff.”

The bases were loaded with one out in the inning when Arcia hit what could have been an inning-ending double play to Iglesias, the shortstop. But Iglesias booted the grounder and compounded that mistake by throwing the ball away. Two runs scored and Iglesias was charged with two errors on one play.

Milwaukee moved ahead when the next batter, Travis Shaw, grounded out to first base, scoring Lorenzo Cain. In the two-run Brewers fourth inning, Grandal hit an RBI double to center field and Cain blooped a two-out RBI single to shallow right field. That was the end of the day for Castillo.

“It is, and at the same time it isn’t [surprising], just because [Castillo is] human. It’s part of being good,” Reds manager David Bell said. “You have starts like this, or days like this. That’s all about the opportunity of making the most of that, and taking what he can from it, and being ready the next time. He’ll get the two extra days' rest between starts, which will be good, too.”

Castillo’s two shortest starts of the season have happened at Milwaukee. On May 22, he lasted just 2 2/3 innings and allowed four earned runs and five hits during a no-decision lost by the Reds, 11-9.

"This is two games in a row that I think we did a good job against a really good pitcher. You have to lay off balls against this guy. We did a really good job of it,” Brewers manager Craig Counsell said. “He's a really tough customer, but you have to be good with balls and strikes against him. You're not going to get a lot of hits, but you can get on base via the walk."

According to Statcast, Castillo’s two-seam fastball was used 11 times, and garnered no called strikes or whiffs while three were put into play. Of the 40 four-seam fastballs thrown, nine were fouled off with seven called strikes and four swings-and-misses. Only 50 of his 96 pitches were strikes.

Now 7-2 with a 2.56 ERA in 16 starts, Castillo’s previous loss was way back on April 3, at Great American Ball Park -- also against the Brewers.

“I feel like when I face them back home in Cincinnati, I’m doing a really good job,” Castillo said. “Especially the last two outings here in Milwaukee, [the Brewers] have been really good. The game is like that. Baseball is like that.”