GEM CEO Tom Reddin told team employees and sponsors the news just before Christmas, causing some sponsors to consider leaving, according to team sources.
Reached for comment Saturday, GEM spokesman Drew Brown chose not to comment.
Sources also said Ray Evernham, who founded the team and sold majority ownership to George Gillett, cleared out all personal possessions from the team's shop, including the 2002 Brickyard 400 trophy he won as owner of Bill Elliott's No. 9 Dodge.
Calls placed to Evernham and Sadler's representation were not immediately returned.
GEM announced earlier this month that it would scale back its Nationwide Series program next season by laying off about 65 employees and having the No. 9 Dodge run a partial schedule in the second-tier NASCAR series.
GEM lost sponsor Unilever to JR Motorsports at the end of the season and doesn't have enough sponsorship in place to run the full Nationwide schedule.
Allmendinger was released by Red Bull Racing late in the 2008 season.
Marty Smith covers NASCAR for ESPN.com.