[cnn-photo-caption image= http://i.cdn.turner.com/cnn/2008/images/06/26/art.rendell.gi.jpg caption=" Rendell says it may be time for Bill Clinton to move on."](CNN) - Pennsylvania Gov. Ed Rendell, a longtime backer of both Bill and Hillary Clinton, said Thursday it's time for the former president to move on if he is still upset about his wife's loss to Barack Obama in the prolonged Democratic primary.
Rendell, whose ardent support of Clinton proved critical in her decisive Pennsylvania win in April, said he's not sure if Bill Clinton is still upset with the ultimate result, but made clear he thinks it’s time for the former president to rally behind the party's presumptive presidential nominee.
Watch: Rendell on Clinton's exit
"Bill's my friend. If that is true the way he feels, he's got to shake it off, get over it, get back in the game and help elect Senator Obama," Rendell said on MSNBC.
"Like everybody else, [he] has to listen to Hillary," Rendell also said. "And Hillary said it best - there's no sense in looking back and wasting any energy."
The former president has come under criticism for remaining conspicuously silent with regards to his support of Obama, even more than two weeks after his wife formally ended her campaign bid. Bill Clinton's office finally released a short statement earlier this week saying the former president is "is obviously committed to doing whatever he can and is asked to do to ensure Senator Obama is the next president of the United States."
But the former president, who was at times sharply critical of Obama during the campaign season, has yet to make any public declaration of support - which has fueled speculation he remains upset with the primary result. Bill Clinton, according to some reports, is specifically upset with Obama's criticisms of his administration over the course of the campaign and the media's treatment of his wife.
But Obama said earlier this week he is confident both Clintons will be enthusiastic supporters as the general election campaign heats up.
“They’re going to want to campaign actively on behalf of the Democratic ticket,” he told CNN earlier this week. “I am going to need them.”