Manchester United last week confirmed reports that Ferguson is booked in for surgery immediately after the club return from their three-week pre-season tour at the end of July.
But that will be moved forward.
Ferguson has always said his health would dictate how long he would carry on as United manager.
He was taken ill at a function in his native Scotland almost 12 months ago, although his nosebleeds were put down to the amount of short flights he had undertaken.
Ferguson subsequently missed pre-season matches in Norway and Germany and also sat out a mid-winter break in Qatar.
David Moyes will replace him, but the choice is staggering considering the Everton manager has won NOTHING in his 11 years at Goodison Park, and his experience in Europe is limited to say the least.
Sir Alex Ferguson will stand down as Manchester United boss at the end of the season having won 49 trophies in the most successful managerial career Britain has ever known.
Spanning almost four decades, from humble origins at St Mirren, it is hard to imagine anyone getting close to the records Ferguson has set.
ST MIRREN
Scottish First Division (1): 1976-77.
ABERDEEN
Scottish Premier Division (3): 1979-80, 1983-84, 1984-85.
Scottish Cup (4): 1981-82, 1982-83, 1983-84, 1985-86.
Scottish League Cup (1): 1985-86.
European Cup Winners' Cup (1): 1982-83.
European Super Cup (1): 1983.
MANCHESTER UNITED
Premier League (13): 1992-93, 1993-94, 1995-96, 1996-97, 1998-99, 1999-2000, 2000-01, 2002-03, 2006-07, 2007-08, 2008-09, 2010-11, 2012-13.
FA Cup (5): 1989-90, 1993-94, 1995-96, 1998-99, 2003-04.
League Cup (4): 1991-92, 2005-06, 2008-09, 2009-10.
Charity/Community Shield (10): 1990 (shared), 1993, 1994, 1996, 1997, 2003, 2007, 2008, 2010, 2011.
Champions League (2): 1998-99, 2007-08.
European Cup Winners' Cup (1): 1990-91.
European Super Cup (1): 1991.
Intercontinental Cup (1): 1999.
FIFA Club World Cup (1): 2008.