"My fingers are bothering me," said Cueto, who lasted six innings and allowed all of Chicago's runs. Speaking through interpreter Erwin Higueros, Cueto continued, "With the fingers not being the way I want them to be, that's affecting them a little bit."
Cueto has pitched virtually all season with a blister on his middle finger. He said another one developed over the weekend in St. Louis while he played catch.
Cueto insisted that missing a start would be a bad idea. If anything, he indicated, he needs to continue pitching so the tender skin will turn to calluses.
"That's not an excuse," Cueto said. "I'm getting hit."
Giants catcher Buster Posey admitted Cueto altered the pitching patterns that made him a two-time All-Star and the ace of San Francisco's starting rotation in Madison Bumgarner's absence.
"It seemed like today they were on the fastball," Posey said, referring to the Cubs sluggers. "We mixed in a little more offspeed than we typically would."
The thought of a subpar Cueto is chilling for the Giants, who probably won't get Bumgarner back until after the All-Star break. Cueto's 18-5 record last season for the Giants demonstrated that he's more than skilled enough to anchor a rotation. The Giants (20-27) need him to be healthy and effective to entertain the notion of reaching the .500 mark, a precursor to achieving contender's status.
In fact, Cueto looked more competent than not while becoming a latter-day version of Mordecai "Three-Finger" Brown, a Cubs Hall of Famer who pitched during the early 20th century. Cueto surrendered one hit besides the trio of homers and struck out eight while walking just one.
Speaking before Cueto updated reporters about his blisters, Giants manager Bruce Bochy said, "Overall, the numbers don't look that good, but he threw better than the numbers are showing. It's hard to say that when you give up three home runs."
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.