Andrew Flintoff will take over as England captain from injured Michael Vaughan for Friday's tri-series match against Australia in Brisbane, the England and Wales Cricket Board (ECB) said on Wednesday.
The appointment came after Vaughan had been ruled out of the one-day international by a hamstring tear that threatens to prematurely end his tour.
Flintoff captained England in their 5-0 Ashes Test loss to Australia but coach Duncan Fletcher later said the burden of leadership had affected his game.
Flintoff has been in great form since Vaughan resumed the leadership and was named man of the match after scoring an unbeaten 72 against New Zealand on Tuesday when England chalked up their first win of an otherwise calamitous tour.
Along with Flintoff's appointment, the ECB said on its Web site that Vaughan's place at the top of the order could go to Ravi Bopara, who was drafted in after an injury to batsman Kevin Pietersen.
England officials were unsure how long Vaughan would be sidelined by the injury, but have called up Lancashire batsman Mal Loye as a precaution.
Vaughan has been allowed to remain with the squad but will undergo a reassessment in the next 48 hours after scans revealed the 32-year-old had suffered a grade one tear.
He injured himself while fielding in England's three-wicket win over New Zealand in Hobart on Tuesday and although he was able to bat, the Yorkshire opener had to call for the assistance of a runner.
He had only just returned to the England fold after two operations on his right knee.
He missed more than a year of international cricket including the Ashes Tests but was recalled for the triangular one-day series after passing a fitness test.
Losing Vaughan for the rest of the series would be another huge blow to England after Pietersen, their best batsman, broke a rib batting against Australia last week.
Loye, 34, is uncapped at international level but was named this week in England's preliminary 30-man squad for the World Cup.
