The Red Devils were beaten 2-0 at Old Trafford in their final fixture of the 2018-19 campaign, with Nathaniel Mendez-Laing grabbing a brace for Neil Warnock's side.
The result extended United's winless run across all competitions to six matches and ensured a disappointing sixth-place finish in the final league standings.
Despite an initial turnaround in fortunes when Ole Gunnar Solskjaer was drafted in to replace Jose Mourinho on an interim basis in December, familiar issues have been raised since his permanent appointment in March.
United only managed to win two of their last 12 matches, with several key players coming under intense scrutiny for their below-par performances - not least Pogba.
During a customary lap of honour after the game on Sunday, Pogba was on the receiving end of abuse from a small portion of the home faithful, with one supporter yelling at him ‘have some f****** respect’.
Club legend Macari, who played at Old Trafford in the '60s and '70s, has condemned Pogba's response to the taunts, as he was seen making a praying gesture and blowing a sarcastic kiss towards the supporters in question.
"Oh come on, come on! I haven’t come here today to [see this]," Macari told MUTV. "If it was somebody else I’d pick on somebody else. Whoever it would be I’d be saying: 'what are you thinking about?'
"Keep your strip on to start with, who else do you see with a strip off?"
Macari was then informed that Pogba gifted his shirt to a young United fan, which sparked an angry response questioning the lack of discipline in the current squad.
"Well he shouldn’t do!" said the Scot. "He should get off the pitch and then send someone out with a strip.
"It’s all about discipline. The discipline here under Sir Alex [Ferguson]"
Major changes are expected at Old Trafford this summer, with Solskjaer tasked with a rebuilding job which might involve several incomings and outgoings in the transfer market.
Pogba has been heavily linked with the likes of Barcelona and Real Madrid, having described playing at Santiago Bernabeu one day as "a dream" earlier this year.