"It was the same thing," Reds manager Dusty Baker said. "We're going to send him back to see the doctor [in Cincinnati]. We'll have to contemplate whatever the roster move is. We'll tell you about it [Saturday]."
In the bottom of the second inning while trailing by a 1-0 score, Cueto could be seen grimacing as he threw a 1-2 pitch to Mitch Moreland that was fouled off.
"I knew that I was feeling bad," Cueto said via translator Tomas Vera.
Cueto was visited at the mound by head trainer Paul Lessard and Baker and immediately walked to the dugout in clear dismay.
Problems actually started in the first inning, when Cueto first felt tight. He allowed a two-out broken bat RBI single to Adrian Beltre to fall into a 1-0 deficit.
"I talked to Bryan [Price, the pitching coach] after I came in for the first inning and said 'I don't feel good, I feel something,'" Cueto said. "He said, 'Let's talk to Dusty.' I said to them I want to keep going and I want to try and see if this goes away."
There were thoughts of shutting down Cueto right then and there.
"He said it was OK. The doctor said he thought it would loosen up, but I guess it didn't," Baker said.
Left-hander Tony Cingrani replaced Cueto in emergency relief and pitched four innings as the Reds went on to lose, 4-0.
Both times when Cueto was placed on the disabled list this season, he was replaced in the rotation by Cingrani.
Cueto was out from April 15-May 20 with a strained right lat muscle. After exiting early from a start at Pittsburgh, he was back on the DL with a similar injury -- a strained right shoulder -- from June 5-16. Friday marked his third start back.
"I don't know how to explain to you what's happening," Cueto said. "I just want to keep working. This is the third time happening. I want to keep working and I will make sure I work until I don't feel anything, absolute nothing. I pray to God that this goes away."
The spate of Cueto injury issues began in October, when he suffered a strained right oblique eight pitches into his Game 1 start vs. the Giants in the National League Division Series.
Cueto has a twisting motion in his delivery where he turns his back to the hitter. He did not believe it was the cause of his injuries this season.
"I don't think mechanics have to do with this," Cueto said. "The pitching coach told me my mechanics are good. If I hurt with my mechanics, it would be in the oblique area."
This setback for Cueto comes at a time when the Reds could use a break. They have lost six of their last seven games.
Cueto is 4-2 with a 3.33 ERA in nine starts. In his previous start a week ago at Arizona, he allowed a season-high seven earned runs and tied a career high with 11 hits in only 4 1/3 innings.
"It is discouraging for him, and us," Baker said. "We'll just have to go back to the drawing board."