Alastair Cook has indicated his time as England captain could be close to an end after the one-day international series against Australia was meekly conceded in Sydney.

England have endured a horror tour Down Under, losing all eight games against Australia in 86 days on tour including the 5-0 Ashes whitewash.

That has left the spotlight on their 29-year-old captain and, after the defeats have piled up, Cook has conceded it has left him contemplating his future.

''I think I'm going to have to make a decision on that after you take stock of the next two games (to end the series),'' he said.

''We'll sit down and talk over a lot of things. I think there will 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 of. We have to look at the reasons why.''

Cook was given the backing to remain in charge by the England and Wales Cricket board during the fifth Test in Sydney a fortnight ago.

Asked if he felt his position has been undermined since, Cook added: ''I don't really want to get dragged into my position. I think it's been two weeks since someone asked me that question - it's been a long two weeks.

''We have kept losing games of cricket and I haven't been able to turn it around.''