Hall of Famer and Cardinals legend Lou Brock has cancer, the club announced Thursday. 

Brock, 77, was set to appear April 25 at Busch Stadium for Budweiser Bash, but that has been cancelled. The Cardinals released the following statement on Brock's health: 

The St. Louis Cardinals announced that Lou Brock has cancelled his April 25th Budweiser Bash appearance at Busch Stadium as he is currently undergoing treatment for Multiple Myeloma. The Hall of Famer was recently diagnosed with the bone cancer and has been undergoing treatment in St. Louis.

Multiple myeloma is commonly known as blood cancer. 

"I am disappointed that I won't be able to make the event," Brock said in a statement. "[My wife] Jackie and I appreciate the prayers and support we have received from our many friends and fans in the Cardinals community. We count ourselves blessed that I am receiving the best possible medical treatment and we look forward to seeing many more Cardinals World Series championships in the future."

Brock played in the majors for 19 years, his first three-plus with the Cubs and the rest with the Cardinals. He led the league in steals eight times and amassed 938 stolen bases in his career, good for second on the all-time list behind Rickey Henderson. Brock won two World Series rings with the Cardinals (1964, '67) and remains wildly popular in the St. Louis area, regularly making appearances at Busch Stadium.