Cueto, who's 6-7 with a 4.59 ERA in 19 starts, said he will begin the healing process by refraining from throwing for at least five days. He is having ointment applied to his fingers in hopes that will ease his discomfort, which he compared -- speaking English -- to being pricked by "a needle."
Cueto felt upset after his outing in Friday night's series opener against the Padres. Cueto allowed three runs and six hits in four innings, his shortest performance as a Giant. He also walked three and struck out five.
"I wanted to help the team, but at the same time I think I'm hurting the team because it's not Johnny Cueto who's pitching out there," he said through interpreter Erwin Higueros. "I feel sometimes like I'm a rookie. I don't know where the ball's going."
Ironically, Cueto's malady virtually assures he'll remain with San Francisco past the July 31 non-waiver Trade Deadline, since his iffy health will make him impossible to deal if the Giants wanted to do so. Cueto remained unmoved when a reporter raised this subject.
"I don't think about that stuff," he said. "Like I said before, it's a team decision if they want to trade me. That's fine. But I'm not thinking about it. My whole main mindset is that I'm going to be here to help the team."
Giants manager Bruce Bochy said Matt Cain, who was assigned to the bullpen when the club believed it would have both Cueto and Bumgarner in the rotation's 1-2 spots, will return to the role he held for nearly 12 seasons. He'll take Cueto's scheduled turn Wednesday against Cleveland at AT&T Park.
The luckiest Giant to emerge from all this was infielder Miguel Gomez, who was vulnerable to being returned to the Minors had Cueto remained healthy. Summoned from Double-A Richmond on July 7, Gomez has impressed Bochy with his clutch hitting. Examples include an eighth-inning RBI single that tied the score against Miami last Sunday and a sacrifice fly in Friday's 5-4 victory here.
"He has the ability to get the good part of the bat on the ball," Bochy said.
Chris Haft has covered the Giants since 2005, and for MLB.com since 2007. Follow him on Twitter at @sfgiantsbeat and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.