Simon had not allowed a hit this spring until Schierholtz launched a shot to right.
"Simon was off the top of the ball," Reds manager Bryan Price said. "The movement was side to side. That's a more difficult adjustment to make."
Joey Votto doubled twice and walked in three trips for the Reds.
Schierholtz turned in a diving grab in right field to rob Kristopher Negron of a hit.
"We had a couple balls hit right on the screws, but fundamentally there are things that don't show up in the boxscore," Price said. "We have to throw strikes and hit the cutoff man. This wasn't a good game. There weren't a lot of redeeming pieces to it."
Cubs: Hammel was signed as a free agent on Feb. 13, the day before spring training opened. He appeared in a "B" game against the Giants on Monday.
He pitched three scoreless innings Saturday, allowing a double to Votto and a single to Skip Schumaker. The right-hander walked three in the first inning but pitched out of the jam.
"I was battling butterflies a little bit," Hammel said. "This was my first time in front of a crowd with a new team. I got through it. I am learning a new team and a new division. These guys (the Reds) are very patient. I threw some close swing-at-able pitches."
Reds: Simon made his third start of the spring. He had not allowed a hit in five innings before Schierholtz homered in the first. The Reds are grooming Simon to be a starter if Mat Latos is not ready to start the season. Strictly a reliever in his two seasons with Cincinnati, Simon is the first Reds' pitcher to throw four innings this spring. He allowed five earned runs on five hits and two walks while striking out one.
Cubs: Starting shortstop Starlin Castro intends to start baseball activities early next week. Castro strained his right hamstring on a steal attempt last Saturday.
Left-handed reliever James Russell (tired arm) threw off a mound. He expects to pitch next week.
Reds: Latos and Jonathan Broxton each threw a bullpen. ... Jack Hannahan had one of his best days throwing to test his surgically repaired right shoulder. ... Sean Marshall is bothered by a sore left shoulder. He missed most of 2013 with shoulder and elbow problems. ... Left-hander David Holmberg, held back from an appearance Friday with a sore right ankle, also threw a bullpen.
A tired Todd Frazier struck out three times against the Cubs. The third baseman had traveled to New Jersey to be with his pregnant wife, Jackie, but spent just 11 hours at home before flying back to Goodyear. The couple is expecting a son, and Frazier's wife was scheduled to be induced Friday. But the doctor decided it was best to wait, so Frazier returned to Arizona.
Schierholtz took a hit away from Negron in the second inning. Negron got even by spoiling Kalish's bid for a second hit with a diving catch of his line drive in the third.
Welington Castillo followed Schierholtz's third-inning single with a solid single to center that skipped off Hamilton's glove. Hamilton recovered and threw quickly to second. Reds shortstop Zack Cozart, with his back to first base, fielded the throw right in Castillo's path for an easy, unexpected out.