United manager Sir Alex Ferguson will no doubt remember the smiling assassin who caused a shock in the States.
Kamara said: "We played Man United on their pre-season tour in 2010. We were Kansas City Wizards back then and we are the only team in America that's ever beaten them.
"I scored a headed goal and got an assist in a 2-1 win. So I may be a marked man against them now!
"But I'm used to being man-marked in America and it just means I have to work much harder because you have to do different tricks to get past people and I really enjoy that."