Even the skipper himself has raised doubts about his future as the top man, in the one-day game at least.
"I think English cricket needs a little bit of a change," Cook told a press conference following the latest drubbing in Sydney. "I think there will be some changes."
Will those changes include a new captain? From a statistical point of view, Cook calling time on his spell in charge of the 50-over side seems a little premature, despite the disaster Down Under.
In 52 matches as one-day captain, Cook's England have been victorious on 29 occasions for a winning percentage of 55.7 percent. That may not sound spectacular, but consider that the last England ODI skipper to win more than half his matches was Michael Vaughan (53.33 percent from 60 games).
Cook's immediate predecessors fared much worse in the one-day arena. England won just 28.57 percent of their ODIs with Andrew Flintoff in charge. Kevin Pietersen fared little better with a 33 percent win rate with Andrew Strauss and Paul Collingwood winning 43.55 percent and 44 percent respectively.
The last captain with a better winning percentage than Cook was Mike Gatting in the mid 1980s. Amazingly, the only England captain with a 100 percent winning ODI record is, wait for it ... Geoffrey Boycott, albeit only from two matches.
|ODI Matches as Captain||Won||Lost||Tied||No Result||Win Percentage|
|Alastair Cook||52||W29||L20||T1||NR 2||55.77%|
|Kevin Pietersen||12||W4||L6||T0||NR 2||33.33%|
|Paul Collingwood||25||W11||L12||T1||NR 1||44.00%|
|Andrew Strauss||62||W27||L33||T1||NR 1||43.55%|
|Andrew Flintoff||14||W4||L10||T0||NR 0||28.57%|
It was only 18 months ago that Cook steered England to the top of the ODI World Rankings for the first time in their history. England's record 10 consecutive victories also occurred under Cook's watch. The home side also came tantalisingly close to victory in the 2013 ICC Champions Trophy at Edgbaston, again under Cook's stewardship. That's quite a bit of captaincy capital in the bank.
Of course things can change as quickly as a Mitchell Johnson bumper, and those successes seem like an age ago. To think that Steven Finn was ranked the second-best ODI bowler in world cricket just six months ago.
A perfect storm of injury, illness, loss of form and retirements combined with an aggressive Aussie resurgence have turned this winter into a tour from Hell for Cook. At the start of the winter even Nostradamus would have struggled to pick the XI that started at the SCG earlier this week.
Of course faults can be found with Cook's captaincy. With the benefit of hindsight, it's unlikely that Ben Stokes would be trusted with the penultimate over in Brisbane for example. There's only so much a captain can do given the tools at his disposal, though.
"I want to be part of a successful one-day team," Cook told journalists in Sydney. "I feel that I'm a good enough player to do that and my record suggests that I can do that."
Despite what the critics say, it certainly does.