United is rated 34th in the world. Ouch. Despite overcoming Bayern Munich last season, the Germans are ranked somewhat higher than the Reds. Chelsea sits fifth thanks to their Europa League win, but Olympiacos is an unexpected presence in the top 10. The Greek club beat the English champions 2-1 in the final to secure its place in the top flight. Now, here's where it gets interesting: United has already been relegated once before - in 1990. The Red Devils came back from three points adrift to Gennaro Gattuso's late penalty shootout winner at Villa Park to avoid the drop. This time around, however, the team would have to win its last four games just to retain its spot. With so much at stake, it's no wonder the club launched a record £750 million transfer campaign ahead of the 2017-18 season. Overall, United is one of the most popular teams in the world with fans. Its $1 billion revenue estimate for 2018 makes it the highest-earning soccer team in the world. However, the club also has the second-highest operating expense ratio at 52%. It's not all glory and cash though; the team has also won several trophies including five Premier Leagues, two Champions Leagues, one FA Cup, and one World Club Championship. It's not easy being green!