Bradshaw was talking to Jimmie Johnson during a commercial break Friday when he used an expletive, The Hollywood Reporter said Sunday.
FOX Sports immediately took to Twitter to apologize for the mistake.
"FOX Sports apologizes for the inadvertent and inappropriate language heard during a commercial break on Friday's edition of FOX Football Daily on FOX Sports 1," the network wrote. "The personalities in the studio, including Terry Bradshaw, were unaware that we'd be going to the set live at that time. We apologize to Terry and viewers who unfortunately heard the comments. We are reviewing our procedures to make sure this does not happen again."