Washington (CNN) - A source close to White House Chief of Staff Rahm Emanuel says that Deputy Chief of Staff Pete Rouse is the favorite to take over as chief of staff on a temporary basis in order to give President Obama more time to find a long-term replacement for Emanuel.
But other people close to the situation said it is too early to determine who will replace Emanuel short-term or long-term because the process is so fluid at this point.
Three Democratic sources close to Emanuel say he's all but certain to run to replace retiring Chicago Mayor Richard Daley and leave the White House.
An announcement is expected to be scheduled for Friday, sources said.
Rouse served as chief of staff in Obama's Senate office and is known to have the president's trust. Democratic officials have told CNN that Rouse, who is known for not relishing the spotlight, has suggested he does not want the chief of staff post long-term. But it is expected he would be willing to help the White House get through a transition and then have an influential role in helping to select the full-time replacement.
Sources familiar with the situation said that once Emanuel makea a firm decision the process will move very rapidly because the chief of staff realizes that he has a lot of work to do to get a campaign off the ground. There is some urgency to the situation, because candidates must gather 12,500 signatures by November 22 ahead of the February 22 primary in the race.
Emanuel is also very sensitive to making sure he leaves the White House in good hands given the critical midterm elections that are fast approaching, as well as other transitions expected to happen after the election. For example, the president's chief economic adviser, Lawrence Summers, announced last week he will be leaving at the end of the year and the search for his replacement is under way.
CNN has previously reported that possible fulltime replacements in the mix include top White House aides Tom Donilon, Phil Schilirro and Ron Klain.
-CNN's Chief National Correspondent John King contributed to this report