But on February 27, 1964, Geiger underwent surgery for a bleeding ulcer at St. Luke's Hospital in St. Louis after having been stricken en route to training camp. Doctors advised him to remain in the hospital for 7–10 days before returning for spring training in Arizona. He was placed on the voluntary retired list at his own request on May 13, and was expected to be sidelined for at least 40 days. He ended up taking the rest of 1964 off because of general fatigue, lack of stamina and an underweight and weakened constitution, but returned the next year.