The two Cubs players visited patients at the Ann & Robert H. Lurie Children's Hospital in Chicago for about two hours.
Both Rizzo, 22, and Campana, 26, have overcome Hodgkin's lymphoma, and they tried to show kids that cancer can be beat.
"Sometimes, we'd go into a room and just say hi, cheer them up," Rizzo said. "Other times, we'd talk to them a little more and tell them Tony and I are both survivors and what we went through, and we know it's not fun. Kids were sitting there getting chemotherapy as we're talking to them. We just tell them to have fun."
Rizzo has visited children in hospitals before, but this was his first in Chicago since being promoted to the big league team June 26.
"They were awesome," Rizzo said of the young patients. "This was definitely the coolest [visit], just because everyone was a big Cubs fan. I met a lot of cool kids, inspiring kids."
Campana and Rizzo took their girlfriends on the visit, and Rizzo said some of the kids preferred to talk to them rather than the players. No problem, he said, laughing. They still got their message across.
"The situation I'm in now, I have a chance to go out and show kids that, hey, there's a light at the end of the tunnel and keep fighting no matter what and always have fun," he said.