Chicago Bears football player Devin Hester will be at Joseph's Marketplace at 6 p.m. Saturday, July 21.
The athlete will pose for pictures and sign autographs during a charity event coordinated by Sideline Marketing.
The charity benefits the Keller family of Marengo. Four-year-old Sean Keller is battling Acute Lymphoblastic Leukemia, and is undergoing treatments at the University of Chicago Comer Children's Hospital.
Sideline Marketing is donating 100% of all profits raised to the Keller family, said Kim Jacobson.
The money will help fulfill Sean's wish of having a pool party with his family and friends, but also assist with medical bills, car repairs and maintenance, and sending the family of six on a weekend get-away, Jacobson said.
Joseph's Marketplace is located at 29 Crystal Lake Plaza, off Route 14 in Crystal Lake.