"I feel bad," Cueto said. "Those things happen when you get frustrated. We're all frustrated. But the manager is the manager and he has chances to do things like that."
Manager Bryan Price said he discussed the incident with his pitcher and called it an atypical reaction from Cueto.
"He wants to pitch -- starters look forward to pitching every fifth day," Price said. "It was not the right way to handle it and we've discussed that and I know he knows that. It's not typical of Johnny by any means to have that kind of reaction, and I certainly don't condone it. It was simply frustration."
Afterward, Cueto (6-6, 2.73 ERA) -- who has been involved in trade rumors as he's in the final year of his five-year contract -- entertained the thought of his Cincinnati days possibly winding down.
"I'm going to leave that in God's hands," he said. "I'm still wearing my Cincinnati jersey. That's what I'm going to be thinking about is that I'm wearing that Cincinnati jersey. We'll see what happens after the All-Star Game. We'll wait to see what happens."
He held the Marlins scoreless until the fourth inning when Casey McGehee notched a two-run double and J.T Realmuto followed with an RBI fielder's choice. Cueto then allowed two unearned runs in the fifth, as Justin Bour notched a two-out, two-run double following a Todd Frazier error.
"They hit some elevated mistakes when they were able to put those five runs together," Price said. "It wasn't his best game. He was actually pretty pitch efficient initially -- had a low pitch count -- but five runs is five runs, and we had to make that decision to take him out."
The five runs Cueto allowed tied a season high, and the five innings were a season low through 17 starts. The outing capped a disappointing weekend for the righty, as he was also beat out by Cardinals starter Carlos Martinez on Friday in the Esurance MLB All-Star Game Final Vote.
"There was a few pitches up -- more than a couple," Cueto said. "Bad pitches. But that's part of the game."
Steve Wilaj is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.