Now 32, Rooney returned to Goodison Park on a free transfer last summer, bringing an end to his 13-year stay at the Theatre of Dreams.
It's a decision the former England captain certainly hasn't regretted so far, having rediscovered his form and knack for scoring goals.
In 17 Premier League appearances for Everton, Rooney has scored 10 goals, including a stunning hat-trick against West Ham in November.
He actually has the same amount of goals as Alvaro Morata and Romelu Lukaku, who joined Chelsea and United last summer for £58 million and £75 million respectively.
Not bad for someone who was supposedly 'finished' six months ago.
Rooney has missed the last two games for Everton, but he returned to face his former employers at home on Monday in search of victory and his 11th league goal.
A question a lot of people were asking before the game was whether Rooney would celebrate if he did score against United.
He didn't manage to, of course, but he probably would have celebrated after what United fans were heard chanting at him in the opening few minutes.
According to a LOT of fans on Twitter, they were shouting, "You fat b*****d," at the striker. Check out the reaction.
Rooney delivered countless trophies for United during his stay at the club, so he probably didn't expect to receive a chant like that from fans who used to worship him.
Banter is to be expected when fans reunite with a former player of their club, but perhaps United's away supporters took it a bit far on this occasion.
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