PITTSBURGH -- Luis Castillo didn't have his best stuff against the Pirates. Maybe it was a sign things wouldn't go the Reds ace starting pitcher's way when his pickoff move cost his team a run.

As the recently hot Reds lineup was cooled off on Saturday during a 3-1 loss to Pittsburgh at PNC Park, Castillo had a serviceable but not robust five innings of work. He allowed three earned runs on four hits and one walk with two strikeouts in his second start of 2022.

"I thought it was a good outing. Maybe not his best, but definitely a step in the right direction," Reds manager David Bell said.

And there was that one balk.

Diego Castillo was batting with runners on the corners and two outs in the second inning when Luis Castillo spun and fired a pickoff move to first base to get Rodolfo Castro. Home-plate umpire Lance Barrett signaled a balk, which permitted Jack Suwinski to score the game's first run. It was Castillo's first balk called this season and eighth of his career.

“It’s been my move my entire career," Castillo said via translator Jorge Merlos. "It just so happened that today it was called for a balk. That’s what happened.”

Bell said he was watching the Pirates’ runner at first base and didn't see the move that warranted a call.

"I went out to get an explanation and was told I wasn’t allowed to do that," Bell said. "I went back in between innings and was told it was because he didn’t step toward first. I just now saw the video. It’s too late. I had the direct conversation with the umpire and will leave it at that."

Following the balk, Diego Castillo hit an RBI single to left field to put the Reds down by two runs.

Luis Castillo, who saw the start of his season delayed because of shoulder soreness experienced in Spring Training, made his season debut on Monday vs. the Brewers and received a no-decision, throwing 4 2/3 innings with three earned runs on 87 pitches during a 10-5 Cincinnati win.

On Saturday, Castillo threw 90 pitches. Again, his sinker and four-seam fastball showed lower velocities than in past seasons; Statcast showed that the sinker averaged 95.2 mph, while the four-seamer averaged 95.5 mph.

“I thought I felt fine the whole game," Castillo said. "My slider and changeup weren’t working as well as I wanted them to, but everything else felt fine.”

Castillo did buckle the knee of Josh VanMeter while striking him out on an 86 mph changeup in the third inning. But to begin the fourth inning, Daniel Vogelbach slugged a 3-2 changeup to the batter's eye in center field to make it a 3-0 game.

“I tried to throw a changeup that was low and below the strike zone," Castillo said, “but that one stayed in the strike zone and he was able to hit it.”

Vogelbach was 0-for-8 with four walks in his career against Castillo entering the night.

Following VanMeter’s strikeout in the third inning, the Reds had to change catchers. On a 2-2 pitch in the next at-bat, Ke'Bryan Hayes fouled a ball hard off the facemask of Tyler Stephenson. After a brief delay, backup Aramis Garcia took over as Castillo's batterymate.

“Of course, it was a tough hit to the face," Castillo said. "It’s unfortunate that he had to leave the game. Hopefully, he’ll be better coming up in the next couple of days. … It’s my first time going with Garcia. It felt really comfortable with him. No issues at all.”

The Reds were held hitless by Pirates starter Zach Thompson into the sixth inning with Castillo's less than robust night more difficult to cover. 

"He got his pitch count higher, so he’ll be in good shape for next time," Bell said. "When you don’t score many runs, it makes it tough on him, but he kept us in the game. All and all, a good night."

Through two starts, Castillo is 0-1 with a 5.59 ERA. As they try to make a long climb out of the bottom of the standings, they will need him to find his groove sooner than later.