I managed Man United against Arsenal, Liverpool and Man City but one fixture was more fierceOne Manchester United rivalry stands tall above all when it comes to ferocity, according to Sir Alex FergusonView 3 Images Manchester United have got more than a few close rivalries (Image: Matt West/Shutterstock)Sir Alex Ferguson admitted Manchester United's fixtures against Leeds United were the scariest he managed. ‌The Premier League giants prepared for the game in Leeds' city centre and required police protection, resulting in the legendary Scotsman ranking the matches against the Whites as the most ferocious he'd encountered. Get YOUR Man United Newsletter Get the best United news, updates and analysis straight to your Inbox courtesy of the Manchester Evening News! ‌"But it never reaches the levels of Leeds United. They begin their Premier League season away to Hull City at the MKM Stadium on August 22, with their first home game coming eight days later when they welcome newly-promoted Ipswich Town.