The England international has already scored 17 goals in 29 appearances for the Red Devils this season, his personal best in front of goals.
Despite his spectacular goalscoring exploits so far, Berbatov believes those around Rashford does not have the necessary wherewithal to help him excel.
The Bulgarian has entreated Rashford to be ruthless and shout at some of his team-mates who possess no match-winning mentality.
The 38-year-old told Betfair: “It was another great goal from Rashford [against City] and a really fast counter attack. United have some very quick players and they didn't take advantage of that.”
“The only trouble sometimes is that the quick players want the ball at their feet and they are not using the space in front of them, but when they try to use the space and make a run the midfield players are not seeing them and not giving them the ball.”
“If I am as quick as Rashford and make three runs and nobody sees me or gives me the ball, on the fourth one I wouldn't waste my energy, it's all psychological. “
“When I was playing, Sir Alex would say ‘Give Berba the ball, and when you give it to him, don't stay, run, because he's going to find you’.
“You need to know your team-mates, who is going to pass you the ball and who is going to make the run, these kinds of things are small details, but they are the most important.”
“Rashford needs to be strong with his team-mates, if he needs to have an argument on the pitch or shout 'f*cking give me the ball,' do it, it doesn't matter, you need to show character and have that will to win.”
“Argue or fight, it doesn't matter if everything is for the purpose of winning the game, you f*cking do it.”
The 22-year-old graduated from the famed Manchester United academy in 2015, and has since played more than 150 times for his boyhood club.
