Gus Johnson, noted for his over-the-top and boisterous play-by-play calls of college basketball particularly during March Madness, is not returning to call games for CBS as the two sides were unable to agree on a new contract. Johnson is in discussions with Fox, sources say. He could play ‘a significant role’ in Fox’s college football coverage, which will soon include the Pac-12. Johnson has worked extensively calling the games for the Big Ten network. He also was mentioned as a candidate for the NFL Network job that went officially to ESPN’s Brad Nessler on Thursday. Besides his college basketball work for CBS, Johnson has also done play-by-play on NFL games for the network since 1998.