Besides calling the 1989 American League Championship Series for NBC, Costas also filled in for a suddenly ill Vin Scully, who had come down with laryngitis, for Game2 of the 1989 National League Championship Series alongside Tom Seaver. Game2 of the NLCS took place on Thursday, October 5, which was an off day for the ALCS. NBC then decided to fly Costas from Toronto to Chicago to substitute for Scully on Thursday night. Afterward, Costas flew back to Toronto, where he resumed work on the ALCS the next night.