Former midfielder believes has yet to regain full fitness since returning from injury and “is just strolling through games”.
The Frenchman made an encouraging start to the season before picking up a hamstrung injury in September that saw him sidelined for 12 games.
Pogba was then sent off against Arsenal at the start of December as the gap between United and rivals Manchester City further widened at the top of the league.
And Scholes has now claimed that the player is struggling to hit top form since returning from his spell on the sidelines.
Speaking on BT Sport, Scholes said: “Where is the Paul Pogba we saw at Juventus? He was all over the pitch, he was battling, he was tackling, he was sprinting to people, he was scoring goals from 25 yards out.
“He is just strolling through games.”
Scholes has suggested that Mourinho may be deploying Pogba in the wrong position which, as a result, is preventing the player from making the most of his abilities.
“Pogba doesn‘t look fit. I wonder whether he is training properly,” Scholes added.
“He does not look like a player who will win you games and that is what you pay £90m for.
“No-one in England should be getting near him, but he is being asked to do a role he is not comfortable in.
“You have to say the manager has to take responsibility for that. Is the manager sending them out not playing the way they want to play? I don‘t know.”