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.
Serling's ending narration was more prophetic than he probably ever could have imagined. He says that, "There's a rumor, unsubstantiated of course, that a manager named McGarry took them to the West Coast and wound up with several pennants and a couple of world championships. This team had a pitching staff that made history." The Brooklyn Dodgers had already moved to Los Angeles two years before by team owner Walter O'Malley, but in the following season after this aired, 1961, Sandy Koufax emerged as a future Hall of Famer, winning 129 games over the next six seasons with an ERA of 2.19. His teammate, Don Drysdale, won 111 games with an ERA of 2.88. The Dodgers won three pennants (1963, 1965, 1966) in those six years and two World Series (1963, 1965).