McTominay has also made a positive impact in Italy, leading Napoli to the league title last season and being named Serie A player of the season.
Schmeichel expressed his confusion over United's transfer policy, suggesting that the pair should have stayed at the club.
"I don't get why those two are at Napoli," Schmeichel said. "Rasmus Hojlund is a massive Manchester United fan and would have been perfect for the club."
Schmeichel believes that United's transfer business has been confusing, particularly in regards to Hojlund's departure.
"We let him go on the stats that he scored very little goals last season, but I've consistently said this for two-and-a-half years - Rasmus Hojlund will be a 25-goal-a-year striker for Manchester United, but he needs service," Schmeichel explained.
Schmeichel thinks that McTominay could have been the perfect option to supply Hojlund if he had stayed at United.
"You only have to see what he's doing at Napoli with Kevin de Bruyne and Scott McTominay to play with - he's scoring goals," Schmeichel said.
United's loss is Napoli's gain, and the Italian side are likely to trigger Hojlund's buy clause and steal him away for free at the end of the season.