Morgan's contract is expiring and won't be renewed, ESPN said Monday.

Miller might continue to handle play-by-play for ESPN, but it won't be in the Sunday Night TV booth. Instead, he might call Sunday Night Baseball and postseason baseball on ESPN Radio.

With Morgan and Miller out of the picture, speculation will instantly begin about who'll replace them behind the microphone for the 2011 season.

Orel Hershiser joined Morgan and Miller in the booth last season. He could slide into Morgan's slot. If ESPN wants to maintain a three-man booth they might pair the former Los Angeles Dodgers pitcher with Jon Kruk of Baseball Tonight or Bobby Valentine if the former New York Mets skipper doesn't land another manager's job.

On the play-by-play side, Dan Shulman looks to be next in line to succeed Miller, who also handles play-by-play for the world champion San Francisco Giants. Or they could take Baseball Tonight host Karl Ravech and give him the play-by-play mike.

ESPN is being increasingly challenged by Major League Baseball's MLB Network, which launched in 50 million homes on Jan. 1, 2009, as one of the most successful cable start-ups in history.

MLB Network's Thursday Night Baseball and Saturday Night Baseball air at least 50 live regular season games. The network's live studio show, MLB Tonight, is the upstart network's answer to Baseball Tonight.

MLB Network has been poaching talent from ESPN. Longtime ESPN analyst Peter Gammons jumped to MLB Network in 2009. Analyst Harold Reynolds was fired by ESPN in 2006 after 11 years with Baseball Tonight after an intern complained about what Reynolds said was a brief and innocuous hug. Reynolds filed a lawsuit for wrongful termination. Reynolds joined MLB.com in 2007. ESPN and Reynolds settled the lawsuit in 2009 before it went to trial.

Some of MLB's other high profile talent includes longtime NBC sportscaster Bob Costas, Al Leiter and Hazel Mae.

Miller received the Baseball Hall of Fame's Ford C. Frick Award this year. Morgan, a two-time National League MVP, was elected to the Hall of Fame in 1990.

"Jon and Joe have contributed greatly to the success of 'Sunday Night Baseball' for the past 21 seasons," said ESPN executive vice president Norby Williams in a statement Monday. "Over the last two decades, Joe went from Hall of Fame player to one of his sport's top analysts and Jon's Hall of Fame voice and tremendous knowledge of the game have connected with baseball fans everywhere. We owe them our deepest thanks for an outstanding body of work."