"General Petraeus is doing a brilliant job but he's been going virtually non-stop since 9/11 [and] he can't do it for ever," Geoff Morrell, the Pentagon press secretary, told The Times.
President Barack Obama and Robert Gates, the Defense Secretary, "are already thinking about that," he said.
The reshuffle will involve the return to Washington of the top five US diplomats in Kabul, including its Ambassador, Karl Eikenberry, as well as the likely departure of Lieutenant-General David Rodriguez, deputy to Petraeus.
The Times is reporting that the moves are expected to coincide with a reduction in US troop numbers, which Obama has promised will start this summer, despite General Petraeus's objections. Is this possibly the real reason for the move? To get Petraeus out before they start reducing troops?
The news that the general himself would be leaving Kabul stunned close observers of US strategy, but the Pentagon insisted Tuesday it was a natural development, given the demands of running the war and Washington's need for fresh blood in a crucial role.
"This is a heck of a demanding job," Morrell said of General Petraeus's central task of driving the Taliban from its strongholds in southern Afghanistan, which US commanders now claim is almost complete. "He will have to be rotated out at some point.
Petraeus has been talked about for a while as a possible successor to Admiral Mike Mullen, chairman of the Joint Chiefs of Staff (CJCS), who is expected to retire in October. Any move would be part of a broader shake-up in the administration, which will also see Defense Secretary Robert Gates retire this year.
More as the story develops.