A second win, 2-1 at home to Perth followed before the disastrous trip to Gosford a little over a week ago and a 2-7 thrashing by Central Coast.
The loss to the Victory was the last straw for Crook, 49, who played his early football at Tottenham before turning out 418 times for Norwich City.
Sydney FC chief executive Tony Pignata, who held that role at the Phoenix before returning to Australia, said he tried, unsuccessfully, to talk Crook out of resigning.
The coaching role at Sydney FC has always been something of a hot potato. Pierre Littbarski, Terry Butcher, Branko Culina, John Kosmina and Vitezslav Lavicka have all held the chalice.
Crook had just six games in charge and will be replaced in the meantime by his assistant Steve Corica, who led the team for some time under Lavicka before retiring and joining the coaching ranks.
The club has indicated they may look to the lower leagues in Italy to find a replacement. They have ruled out any suggestion that Del Piero will step into the role.
Elsewhere, the harsh reality of life in the league is hitting hard in Wellington.
Three weeks into the season the Phoenix were sitting pretty with a win and two draws; fast forward just three weeks and it is obvious how that situation has changed.
The Phoenix have slumped to three straight losses - as have defending champions Brisbane Roar who are the only team below them on the points table.
With their 1-0 win over the Phoenix on Sunday, Graham Arnold's Central Coasters have gone from fifth to first with three straight wins, edging ahead of early-season pacesetters Adelaide United on goal difference.
It has been a horror run for the Phoenix who have also seen their plus-two goal difference after three games slump to minus-two after six. Only Western Sydney Wanderers, with four, have scored fewer goals than the Phoenix, who have scored seven.
It will not get any easier with road trips to Newcastle and then Perth to come.
On December 9 they will again face Sydney FC at home.
That shapes as a battle royal for both clubs.
