The handover was originally scheduled to take place in September, when Petraeus is supposed to start his new job as director of the CIA. But administration officials are trying to give Petraeus a bit of a breather after years of leading troops in Iraq and Afghanistan, Defense Secretary Robert M. Gates said Tuesday.

“I think we would like to have a change of command somewhat sooner, and it is to give General Petraeus a little time,” Gates said in an interview with The Washington Post. “The last four-and-a-half years, it’s been pretty wild for him.”

There’s one potential obstacle to the change: the Senate.

The Senate first needs to confirm Allen’s nomination to become commander of U.S. and NATO forces in Afghanistan, as well as his promotion to four-star general. The Senate Armed Services Committee has scheduled a confirmation hearing for Allen for next Tuesday.

While Allen is not expected to have a hard time winning approval, Congress is already eyeing its summer recess and it’s unclear if they’ll be able to cram Allen into their schedule before August.

“Whether or not that even happens depends on the Senate’s schedule,” Gates said. “It may or may not happen I guess is the way I’d put it.” He said Obama wants Petraeus to start at the CIA by Sept. 1.

Allen most recently served as deputy commander of the U.S. Central Command, based in Tampa, Fla. If confirmed, he’ll be the first Marine to lead all U.S. forces in either the Afghan or Iraq wars. Since last month he’s been serving as a special assistant to Adm. Mike Mullen, chairman of the Joint Chiefs of Staff.

The Senate has been focused on other key national-security appointments made recently by Obama. On Wednesday, the full Senate unanimously confirmed Leon Panetta’s nomination to become defense secretary. He’ll start his new job July 1, taking over for Gates, who is retiring after four-and-a-half years.

On Thursday, meanwhile, the Senate Intelligence Committee is scheduled to hold a confirmation hearing for Petraeus’ nomination to succeed Panetta at the CIA. All these appointments come on top of the Obama administration’s pending decision on troop withdrawals in Afghanistan.