On Friday, Kasallis, his girlfriend, Ashley Souk, and his family were at Wrigley Field as part of the pregame ceremonies.
"When my son asked, [Rizzo] said, 'I'll do my best,'" said Donna Kasallis, Mike's mother. "To not only hit the home runs, but to remember to do that [touch his lips and point], that's what was so touching."
Rizzo and Kasallis have exchanged text messages since that July day and since Mike began chemo treatments. Rizzo knows what Kasallis is going through. In 2008, the Cubs slugger was diagnosed with Hodgkin's lymphoma. He has recovered and is ranked second in the National League in home runs entering play Friday.
Kasallis, of suburban Buffalo Grove, Ill., graduated from Illinois State in May, and he was diagnosed on June 20 with pancreatitis.
"We have six months and two years to go," Donna said of the chemo treatments, which includes weekly sessions for six months, then monthly treatments for two years. She said the good news is that doctors say Mike is already in remission.
Kasallis was at the Ann & Robert H. Lurie Children's Hospital in Chicago when Rizzo visited that morning. What was their reaction when Rizzo homered that night at Wrigley Field?
"I started crying," Donna said. "[Mike] got all choked up. And then to do it again -- we started crying."
Rizzo had said the visit brought back memories of his own experience.
"This one hit more at home for me," Rizzo said in July about meeting Kasallis, his mother and his girlfriend. "I usually don't get flashbacks, but I did this time."
When Rizzo visited Kasallis in the hospital, Donna said her son perked up for the first time since the diagnosis. She had taken Mike to see a doctor because he was complaining of stomach pains, and it turned out to be much more serious. Donna said they were lucky to get a diagnosis so early.
"It was the first time I'd seen him with any spark," Donna said of Rizzo's visit. "It was like I saw my kid again that day."
Rizzo's mother, Laurie, joined him at the hospital, and Donna asked for advice.
"I said, 'How do you deal with this?' and she said, 'One second at a time,'" Donna said.