The Chicago Fire TV show was filming at Wrigley Field on Wednesday

Excerpts from variety.com:

Two Chicago Cubs players will guest star on “Chicago Fire.” Chicago Cubs Kris Bryant and Jake Arrieta, as well as NBC Sports’ Mike Tirico, will appear in the season five finale of “Chicago Fire,” airing May 16. In the episode, a young Cubs fan is in a serious car accident and is not only injured but also loses his entire baseball card collection in the flames. Firefighter Christopher Hermann (David Eigenberg) attempts to cheer the boy up by giving him an unforgettable experience.

thanks Dan