Keith Olbermann will return to sports for the first time in six years to join Cris Collinsworth as co-host of the pregame show for NBC's Sunday night NFL telecasts. Olbermann, who currently hosts a prime-time newscast and opinion show called "Countdown with Keith Olbermann" on MSNBC, will join with host Bob Costas and analysts Jerome Bettis, Tiki Barber and Peter King on NBC's "Football Night in America."