Solskjaer made Maguire the most expensive defender in the top flight when he signed him from Leicester City for a deal worth £80m in 2019.
Manchester United wanted to sell the defender to West Ham this summer but he refused to leave after the two sides failed to reach an agreement over a payoff.
Maguire is now the fourth or fifth-choice centre-back in the squad and is not the most popular member of the squad amongst some fans due to his refusal to accept a move to West Ham.
However, Solskjaer insisted that the defender was one of his best signings as he came in and lifted the mood inside the dressing room and improved the defence.
The former Manchester United manager feels that the amount of abuse he is being forced to tolerate at the moment is completely uncalled for.
Solskjaer told The Athletic: “Harry Maguire – it’s a disgrace that he’s getting so much abuse.
“I feel sorry for him, but he’s a strong lad and I hope it turns for him.
“He raised our defence big time when he arrived and lifted the mood around the place.”
Maguire will have a year left on his contract if he is still at Manchester United at the end of this season.