Sharpe is not surprised to see Maguire performing well and claims the defender is living up to expectations following his £80million move from Leicester City in 2019.
"I think what happened in the summer on his holidays has spilled over a little bit," Sharpe told Stadium Astro of Maguire.
"I think he's had a couple of not so good games and people have picked up on it.
"But I think the consistency levels since he got to United have been phenomenal.
"He has shored up the defence, he reads the game really well, he can play. You can tell that as a kid he was more of a midfielder than a defender because he's more of a footballer than just a stopper.
"I think he has been fantastic for the club. Criticism is a bit harsh."
Sharpe added: "You go and play for a club like Manchester United, who are one of the biggest in the world, it's part of the territory. You have to take the criticism.
"You are there to be shot at, but no-one generally criticises you more than yourself. I think he has handled things well.
"It's a difficult place to go. Stepping up from any club to go to Manchester United is difficult and I think he's handled it with class."