<P> Busby returned to the manager's seat on a temporary basis and pulled the team well clear of relegation, eventually matching the previous year's 8th - place finish . Frank O'Farrell of Leicester City became the club's new manager in the 1971 close season, after unsuccessful approaches for Jock Stein of Celtic, Don Revie of Leeds United and Dave Sexton of Chelsea . Despite starting the 1971--72 season well and raising hope that O'Farrell would be a good successor to Busby, a run of seven defeats from 1 January meant they were to finish in eighth place for the third successive year--a dismal showing for a club who had appeared capable of winning the title for at least the first half of the season . However, the season did see the signing of 22 - year - old Aberdeen defender Martin Buchan, who would play a key role in later successes for United . </P> <P> At this time, George Best was becoming a problem, continually flouting the rules and getting into various disciplinary troubles . At the end of the 1971--72 season, one day short of his 26th birthday, he announced his retirement, only to turn back on his decision and announce his intention to play again within days . </P> <P> While Best's erratic behaviour didn't help, United continued to struggle, opening the 1972--73 season with a disastrous nine matches without a win . Following a 4--1 defeat to Tottenham Hotspur on 28 October 1972, chairman Louis Edwards planned to sack O'Farrell and made an audacious move for former Manchester City manager Joe Mercer, but O'Farrell was away on a scouting mission on the day Edwards intended to sack him, and the 58 - year - old Mercer (who was to retire from football within two years) turned the offer down anyway . </P> <P> United's form briefly improved after this, allowing O'Farrell a stay of execution, but a 5--0 thumping by relegation rivals Crystal Palace just before Christmas proved too much, and led to the manager's dismissal on 19 December . In a way it was the end of an era, with Bill Foulkes having retired, Bobby Charlton's testimonial having been held the previous day and George Best once again announcing his retirement on the same day . Charlton, now 35, would play his last match for the club at the end of that season . </P>

When was the last time manchester united was relegated