Olbermann claimed that when he worked for him Rosen held as many as 11 different jobs, while Rosen says he didn't think it was that many but admitted he worked so often that he could easily have forgotten some of them. He left UPI in 1981 when his ESPN workload and compensation became a living wage by itself. Rosen was employed by ESPN from 1979 to 1988, calling a variety of sports for the network including hockey, college football, boxing, table tennis, Australian rules football, college baseball, collegiate wrestling and NASL soccer. He handled play-by-play for NHL Radio, a partnership between the NHL and Westwood One. He has called the Stanley Cup playoffs on the radio for many years, as well as the 2002 and 2006 Winter Olympic Men's Hockey Tournaments. Rosen has also been a play-by-play announcer for "NFL on Fox" since 1996. Rosen also called preseason NFL games for the Chicago Bears from 2009 to 2017, when he was replaced by Adam Amin, and previously did this for the New York Giants for several seasons. Rosen's broadcasting partners have included Heath Evans, Kirk Morrison, Ron Pitts, Ray Bentley, Jerry Glanville, Tim Green, Brady Quinn, Matt Millen, Bill Maas, Brian Billick, Tim Ryan, Ronde Barber, Chad Pennington, Daryl Johnston, Cris Carter and John Lynch and Charles Davis. Rosen was also the lead boxing announcer for the MSG Network until 1993. In 1989, he won the Sam Taub Award for excellence in boxing broadcasting journalism. Rosen has also worked for Versus (now the NBC Sports Network) calling games in the first round of the Stanley Cup Playoffs. He was the play-by-play announcer for the Stanley Cup Finals on NHL Radio from to . Rosen was also a radio play-by-play announcer for the New York Cosmos. His call "It's a Cosmos Goal" predated and could be considered as the basis for his trademark power play call.