PHOENIX -- The Reds' rotation appears headed for some upheaval -- with the potential removal of one, and maybe two, struggling starters soon. But one pitcher who looked to be on the road of continued improvement was Luis Castillo. Following a rough April, it's been a decent May.
Castillo is not immune from mistakes though. In a 5-2 Reds loss to the D-backs at Chase Field on Tuesday, he paid dearly for them. Following a two-out walk on five pitches to Jake Lamb in the first inning, Daniel Descalso hit a two-run home run that made it 2-1, and Arizona never looked back.
"That was one of the things today that hurt me the most, the walk with two outs and the homer. Unfortunately it happened tonight," Castillo said via translator Julio Morillo.
It was a 2-1 count when Descalso crushed a 96 mph fastball up and over the plate and easily cleared the right field fence.
"I was supposed to go inside with that pitch," Castillo said. "The pitch caught too much of part of the plate. He put a good swing on it for a homer."

In the third inning, a leadoff walk to Jarrod Dyson led to another run when next batter Ketel Marte hit an RBI double to right field. Lamb added a sacrifice fly that made it a three-run deficit for Cincinnati.
An unearned run scored against Castillo in the fifth when shortstop Alex Blandino's two-out throwing error in the dirt to first base skipped off Joey Votto's glove and scored Dyson.
"I was trying to work 100 percent and do my job as I always do. But, you know, it was one of those nights where the small details were not there," Castillo said. "When you make those mistakes, you get hurt. Unfortunately, I lost the game today."
Castillo finished with five runs (four earned), four hits and three walks over five innings with six strikeouts. He threw 90 pitches. Entering the game, he was 3-1 with a 2.83 ERA in five starts in May after he had a 7.85 ERA through his first six starts of 2018.
"Young pitchers, there is a lot of ups and downs," Reds interim manager Jim Riggleman said. "We love his arm and his competitiveness and his professionalism. So we're fortunate to have him, and we'll just keep running him out there."
Against Arizona starter Zack Godley, the Reds took a 1-0 lead in the first inning after Blandino hit a leadoff double and scored from third base on a Scooter Gennett groundout. Eugenio Suarez led off the top of the sixth inning vs. Godley with a booming homer to center field.

Although David Hernandez followed Castillo with two spotless innings and Amir Garrett worked a scoreless eighth, there was only one more hit from Cincinnati following the Suarez homer.
Since winning a three-game series over the Pirates May 22-24, the Reds have dropped four of five games on their current road trip -- including the last three.
YOU GOTTA SEE THIS
Suarez's homer against Godley was no cheapie. According to Statcast™, the 111.5 mph exit velocity was the hardest-hit long ball of his career, and the projected distance of 451 feet tied for his second-longest. It was also the hardest-hit and longest homer of the season for the Reds.
The moonshot was the third home run in the last six games for Suarez and his eighth his month. He's tied for second in the National League in May homers and is first in the Majors with 28 RBIs for the month. He is tied with the Cubs' Javier Baez for the NL RBI lead on the season, with 42.

HE SAID IT
"We'll take the effort and intensity. Sometimes when you're losing ballgames like we are, you have to look for some positives. I liked the way Luis competed. I liked the way our bullpen shut things down for us. At the end of the day, it's a loss and we're not satisfied with it. We've got try and build on any positives we have." -- Riggleman, whose club dropped to 19-37 on the season
UP NEXT
The Reds will cap their three-game series vs. the D-backs at 3:40 p.m. ET Wednesday with Sal Romano (2-6, 5.89 ERA) on the mound trying to turn things around. Over his three starts since May 14, Romano has given up 18 earned runs, 22 hits and 12 walks with 13 strikeouts over only 12 2/3 innings. Arizona will be countering with left-hander Patrick Corbin, who is 5-1 with a 2.47 ERA.