Paul Douglas, who had drinking habits, was originally cast to play McGarry but onstage began to look red and read raspingly, and it wasn't until his coronary-related death days after the episode was completed that it was realized he had been suffering poor health rather than reaction to drink. Because the episode was supposed to be a comedy, Rod Serling was reluctant to let it be broadcast with Douglas' impending death essentially captured on film. When CBS refused to pay for the episode to be re-shot, Serling personally underwrote the $27,000 it cost to have Jack Warden brought in to replace Douglas and to have some scenes re-done with Warden in place of Douglas.
When Casey returns to the locker room with a heart, the teammates surrounded him welcoming him back included an uncredited Dom Deluise.
In the second scene in the hospital (with the commissioner reading the rule book), there is an oil can on the headboard of Casey's bed. No reason is given for this to be present. No character even mentions it. An obvious nod to the Tin Man in The Wizard of Oz (1939), also built without a heart.
Robert Sorrells, who plays Casey, became a reclusive heavy drinker in his later years. On July 24, 2004, he walked into The Regency Lounge, a Simi Valley bar, and shot two customers, killing one. He was caught three blocks away by police, was arrested for murder, and spent the rest of his life in a prison in Vacaville, California. He died there in July 2019, age 88.