England cricket hero Andrew Flintoff is suffering from deep vein thrombosis in his right calf after knee surgery, say reports.
The 31-year-old all-rounder underwent an operation following the conclusion of this summer's Ashes tournament.
A Sky News report said Flintoff could be sidelined for a minimum of six months.
An England and Wales Cricket Board statement read: "Andrew Flintoff recently suffered a common complication of surgery, a minor deep vein thrombosis in his right calf. This will require a simple course of treatment and will not complicate his recovery from surgery."
Flintoff retired from test cricket after playing in four of the five Ashes tests against Australia. England won the series 2-1.
He had announced his retirement before the second test at Lord's following the latest in a series of career-threatening injuries.
But 'Freddie' is hoping to continue playing one-day and Twenty20 internationals.