Another demoralising defeat at the SCG on Sunday night not only secured Australia an unassailable 3-0 lead in the five-match one-day series but left Cook indicating he was weighing whether to quit the leadership post after a horror summer.

The England Test and one-day captain insisted he wanted to carry on in charge in the wake of the team's 5-0 thrashing in the Ashes but a fortnight later he is far from as sure.

"It's been two weeks since somebody has asked me that question and a lot has happened in two weeks. We've kept losing games of cricket and we haven't been able to turn it around," Cook said.

"I can't answer that question now because I'm in the middle of the series and I don't know how I'm going to feel when I get home."

It was unclear whether Cook, who had not lost a Test series as captain until this summer's Ashes, was speaking specifically about possibly departing the Test or one-day leadership but he appears likely to step back in some capacity.

"I think I"m going to make a decision on that stuff after you take stock after the next two games," Cook said.

"We'll sit down and talk (about) a lot of things. I think there will probably be some changes. I think English cricket needs a little bit of a change as well. The last few months we haven't played the cricket we are capable are doing. We have to look at the reasons why."

The 29-year-old opener said the England team "deserve the stick we get" after a winless tour against Australia but shot down any suggestion he would be the latest casualty of the three-month visit.

Jonathan Trott, Graeme Swann and Steven Finn have all left the tour for varying reasons since it began in October but despite being shattered at how events have transpired Cook said he would not be flying home early.

"I've got a job to do, to try and turn this around and try and win one of these games. That's the task at hand," Cook said. "I'm competitive, I leave everything out on the pitch so I wouldn't ever question why I wouldn't be here these next two games."

Australia captain Michael Clarke endured his own tough period last year when his team were winless across all formats about seven months and knows the predicament Cook is faced with.

"Defeat takes a toll," Clarke said. "A lot of the time when you're not performing well as a team the captain is in the spotlight and that's a big part of captaincy, you're accountable. It's extremely hard there's no doubt about it and unfortunately I've experienced it a fair bit already through my captaincy. Any time you're not winning that certainly makes life harder as a Test captain."

Asked whether he felt sympathy for Cook's plight, Clarke said:

"I don't think feeling sorry for an opposition captain is the right thing to feel. To a certain extent I know what Alastair is going through because we've experienced some tough times as a team and it's tough as a captain, there's no doubt about it.

"We've experienced a lot of defeats in the past couple of years...and I think it'd be very silly for me to allow myself to try and put myself in Alastair's shoes because I'm not there."