6 controversies Sir Alex Ferguson had as Manchester United manager

#3 His implicit role in Preston's relegation

Darren Ferguson's sacking triggered a collapse at Preston

Sir Alex Ferguson has a son Darren who played under him before going into management.

He has largely had mediocre a career as a coach (understandable considering the lofty heights reached by his father) and was appointed coach of Preston North End in the Championship in January 2010.

His spell at Deepdale was to be shortlived however, as he was relieved of his duties later that year with Preston bottom of the Championship having lost 24 out of its first 49 games under Darren.

Upon hearing the news of his son's sack, Sir Alex Ferguson recalled three players who were on loan at the club, while close friend Tony Pulis also followed suit by recalling two Stoke players who were on loan at Preston.

This vengeful act saw Preston lose five key senior players in the space of three days, with the result being that they were relegated to League One at the end of the season.

Fans of Preston still hold resentment to Ferguson and Manchester United till this day as they hold them responsible for the club's 2010 relegation which saw security beefed up ahead of a Cup clash with United in 2015.