During a staff meeting Monday when he made the announcement, Daley said his role was evolving, a senior aide who attended the meeting told The Wall Street Journal.
In recent weeks, Daley has focused more on managing relations with influential outsiders, aides said.
The redefining of Daley's duties, agreed to by President Obama, is meant to help the president's team operate more smoothly as it prepares for the overlapping demands of governing while campaigning for re-election, people knowledgeable about the situation said.
Rouse was Obama's interim chief of staff before Daley.
In an interview last week before the formal announcement, Daley said he was doing more, not less, the Journal said.
"The president challenged us all to pick up our game after the summer and I think we're all trying to do that," he said.