On the back of their five-nil Ashes triumph, Australia claimed the limited overs series in emphatic style on Sunday at the SCG by hammering England by seven wickets with 10 overs to spare.
The win gave Australia an unbeatable three-nil lead in the best-of-five match series as England's tour sunk further into the mire.
After the match Cook said he would review his role as England skipper after the tour is over.
"I think I am going to have to make a decision on that stuff after we take stock after the next two games," Cook said.
"We are going to have to sit down and talk about a lot of things.
"I think there will be some changes, I think English cricket needs a little bit of a change as well.
"Obviously in the last few months we haven't played the cricket we are capable of and we have to look at the reasons why but this is not really the time and place to discuss that."
After the Sydney Test two weeks ago Cook was backed to remain as skipper by the England and Wales Cricket Board and stated his own desire to remain in the role but he indicated things might have changed since then.
"I don't really want to get dragged into it. It's been two weeks since someone has asked me that question and a lot has happened in two weeks," he said.
"We have kept losing games of cricket and I haven't been able to turn it around."
Cook's demeanour after his side's eighth straight loss to Australia at least indicated he could step aside as captain of the one-day international side.
"We deserve the stick we get because we haven't won anything," he said.
"I have a job to do to try and turn this around and try and win one of these games, I am going to leave everything out on this pitch."