The disgruntled supporter, who appeared to be drunk during the call, had rung Greater Manchester Police hoping to talk to United's former manager following Wednesday's League Cup elimination at the hands of Sunderland.
United were looking to overturn a 2-1 first-leg deficit in the Old Trafford clash but exited the competition at the semi-final stage via a penalty shootout, after Javier Hernandez's last-gasp strike in extra-time saw David Moyes' side win 2-1 on the night.
It was the latest in a series of disappointments for Moyes, who has seen his side slump to seventh in the Premier League table, 14 points adrift of leaders Arsenal and six behind the UEFA Champions League spots.
The Sunderland setback was a step too far for one fan who decided to dial 999.
GMP released a recording of the conversation, in which the caller said: "Could I speak to Sir Alex Ferguson please? The result is all wrong.
"We had extra time and it was a total load of rubbish. I want to report a crime, the crime is that Manchester United were absolutely knackered."
GMP warned the man about the appropriate use of the emergency services, but took no further action.
A statement released by GMP read: "Silly calls like this one are thoughtless and can make a difference in a life and death situation.
"As a force we receive thousands of emergency and non-emergency calls, which is why I would urge those considering making such pranks to think twice.
"Our call handlers should be able to focus their efforts on real emergencies as they are happening. Hoax calls could delay an officer responding to a real emergency.
"You wouldn't want your own emergency call being delayed by someone tying up a line with a hoax."
