CINCINNATI -- Bailey Falter's first turn through the Reds’ order Monday at Great American Ball Park was perfection. Nine up, nine down, with no hard contact and a strikeout to boot.

The second time through the order was anything but perfect. The Reds piled five runs against him, and the Pirates would end up losing, 11-5.

Talking postgame, Falter didn’t think it was a mechanical issue that caused his fourth-inning struggles, but a matter of execution, which stemmed from something you don’t hear ballplayers admit too often.

“Just got a little tired,” Falter said. “Just wasn't executing a lot of pitches. A lot of first-pitch balls compared to the first three innings. So, they just capitalized on it."

Falter would later again allude to fatigue as the reason why his fastball execution was not as sharp as usual, saying, "Probably just got exhausted. Maybe a little tired. I don't know."

Falter’s usual recipe for success centers around four-seam fastball command, making up for his low-90s velocity by getting good extension on his delivery and spotting it up in the zone. He did that for three innings Monday, but in the fourth, the fastball slipped into the lower half, often hanging in the middle, as seen on his pitch chart of fastball results in that fourth inning:

It started quickly with ground-ball singles by Jonathan India and Elly De La Cruz before Spencer Steer and Stuart Fairchild followed with two-run doubles. All four hits had exit velocities well north of 95 mph, the cutoff for hard contact, and a sacrifice fly by Levi Jordan extended the Reds’ lead to 5-1 in what would be a 31-pitch inning. Falter did not go back out for the fifth.

"I think the first time through he did a really good job executing the fastball at the top of the zone, inner half of the plate,” said Pirates manager Derek Shelton. “It looked like in the fourth inning the ball just leaked back towards the middle, and because of that, we saw the hard contact."

The Pirates’ middle relief couldn’t keep the game competitive in Falter’s absence. Justin Bruihl, who opted out of his Reds Minor League contract to sign with the Pirates earlier this month, allowed two runs to his former club. Dennis Santana was removed early with a right arm contusion after being hit by a comebacker. Daulton Jefferies surrendered four runs, the loudest being a homer by De La Cruz that landed on the riverboat deck above the batter’s eye in center. The bullpen is shorthanded at the moment after closer David Bednar went on the injured list Sunday, and needing to cover extra innings Monday didn’t help.

Falter has now lost each of his four starts in June, allowing almost as many runs this month (15 runs, 14 earned, over 19 innings) as he did in April and May combined (17 over 60 1/3 innings). He was coming off of a seven-inning, two-run performance his last time out against the Reds at PNC Park, and some of those earlier runs allowed in June were seemingly more a product of batted-ball luck than anything, a product of a pitcher that relies more on weak contact than strikeouts. But results are results, and they indicate a June swoon for the southpaw.

Falter’s claim of being tired is worth monitoring moving forward. Monday night was a very muggy 85 degrees right on the banks of the Ohio River, so it was hardly ideal pitching conditions. But with so much attention being paid to the workloads of rookies Jared Jones and Paul Skenes this year, Falter is also on pace to blow past his previous high for innings.

In 2022, he threw 131 2/3 innings between the Majors, Minors and a brief cameo in the playoffs. It was the most competitive innings he’s thrown in a full season as a professional. Last year, he tossed 130 2/3 frames. If Skenes and Jones are going to be monitored because they had never pitched 130 innings, Falter is basically in the same boat.

Of course it could be that Monday was just an anomaly, a product of the weather or whatever, and that he will be reenergized the next time his number is called. But Falter was an important part of this team keeping its head above water and still in the playoff mix the first two months of the season. The Pirates are going to need a bounceback from him.