Martin, who was en route to Cleveland for a tour stop, stopped by the Lou Malnati's Pizzeria near Midway International Airport on the Southwest Side.
He wanted to meet Heidi Hernandez, who was gifted with club seats for Coldplay's concert Thursday at Soldier Field in Chicago. Chance the Rapper had hooked her up with the tickets after her boss at Lou Malnati's reached out to the Chicago rapper.
Hernandez gave Martin a long hug when he arrived at the restaurant. The two took selfies and talked at the restaurant, where Hernandez works.
Before leaving, Martin invited Hernandez, her boyfriend and her Lou Malnati's manager to fly to Seattle to see the band's Sept. 23 show and sit in the front row.
He also got Hernandez tickets to Saturday night's Bruno Mars concert at the United Center.
Hernandez was diagnosed with primary sclerosing cholangitis at age 3. She received a liver transplant from a donor at the age of 9, but unfortunately the disease came back with the new liver. Heidi was also recently diagnosed with hepatitis autoimmune and is showing signs of liver failure again.
Doctors say she needs a second liver and she encourages people to be organ donors.
"I got into a really bad depression where I wouldn't even be able to go to school. And I just started listening to [Coldplay's] music and it made me feel a lot better," she said.