President Obama might have more opportunities to get some "fresh legs" in the White House, according to a top administration spokesman.

White House Deputy Press Secretary Bill Burton hinted on Thursday at more opportunities the president might have to shake up senior staff and rejigger his administration's operations.

"At the end of a president's first two years in office, there are often changes that occur," Burton explained on the liberal Bill Press radio show. "There's going to be a lot of different things the president will have the opportunity to inject some fresh legs and ideas."

Burton wouldn't confirm the expected departure, as soon as Friday, by White House Chief of Staff Rahm Emanuel to pursue a bid for mayor of Chicago.

The administration's already seen turnover elsewhere. Peter Orszag left his post as director of the Office of Management and Budget (OMB) earlier in the summer, and Christina Romer resigned as the chairwoman of the Council of Economic Advisers (CEA) to return to teaching.

Senior adviser David Axelrod has said he expects to leave the White House in 2011 to begin focusing on Obama's reelection effort, and Defense Secretary Robert Gates has suggested he'd like to leave in 2011, as well.

Speculation elsewhere has centered around whether Press Secretary Robert Gibbs would leave his day-to-day position in front of the cameras to move to a more senior adviser role, and whether David Plouffe, Obama's political guru from the 2008 campaign, might take a bigger role in the White House.