Carroll: Man Utd boss Ferguson always good with me
The Northern Ireland goalkeeper is back in England after leaving Denmark's Odense.
He won a Premier League medal in 2003 and an FA Cup medal 12 months later and admitted to The Sun: "Sir Alex brought me on against Millwall with five minutes to go because he said I'd done well in the semi-final.
"He actually offered me a new four-year contract in 2005 but would not guarantee first-team football.
"Yet he was always fantastic with me and, even when I left, he always said if I ever needed anything I should ring."