Amorim has been given a crash course in life at United after an inconsistent start to his reign since he succeeded Erik ten Hag at Old Trafford.
Now Sharpe has told sundayworld.com that the United manager has to find a solution to the lack of cutting edge in his team, especially with striker Marcus Rashford confirming he wants to leave the club.
Rashford declared on Tuesday he was “ready for a new challenge” after United boss Amorim decided to omit the 27-year-old academy product from the team for the 2-1 derby win at Manchester City on Sunday.
While Rashford’s current deal at the club runs until 2028 and Amorim insisted he wants him to stay, the England international was left out of United's Carabao Cup defeat at Tottenham on Thursday.
Asked if it was a mistake to leave Rashford out, Amorim said: “No it is not. I feel that I do the right thing for the team so it’s never a mistake. We have to make a selection.
“Sometimes, like in the game, you feel that some of the guys go inside of the pitch and change a little bit of the game. Sometimes it is like that.
“I think it was not a mistake because I feel I am always doing the best for the team in my way of seeing things.”
Now Sharpe, who was part of Alex Ferguson's first Premier League title-winning team, has suggesting finding a solution to the United goal threat should be top of his wish list when he looks to put his own stamp on the United squad.
"I think a goal scorer should be the priority for Amorim, but they are not easy to find in the January transfer window and they don’t come cheap when it’s Manchester United that comes calling,” said Sharpe.
"Rasmus Hojlund is going to be a top player, but he is still young and learning his trade. He has also picked up a few injuries and that can happen to young players at the start of their careers. He is a physical player who gets battered around a lot.
"Signing a striker is not easy, but with Rashford going, maybe the wage bill will be a bit lighter and they can look to go after someone else."
Sharpe went on to back Amorim to make a difference at United, as he has been impressed with his opening few weeks at the club.
"The new manager has handled things very well,” added Sharpe. “He has handled situations well so far and he is trying to introduce a new formation, which will take time.
"He set a line in the sand on the standards he expects by leaving out Rashford and (Alejandro) Garnacho, he is dealing with the media very well, so it has been a positive start from Amorim.”