The Daily Mail's Chris Wheeler wrote that Pogba's wish to join the Blaugrana is now United's main concern, not his fractious relationship with Mourinho.
The Red Devils chief was said to have been "angered and surprised" by the France international's comments following the 2-1 league win over Leicester on Friday, when he told the press: "There are things I can't say, otherwise I will get fined."
According to Wheeler, Pogba has already told team-mates and United executive vice-chairman Ed Woodward he wants to leave the club. His agent, Mino Raiola, is also understood to have terms agreed with Barca, who had a bid for the midfielder rejected this summer and aren't expected to complete a move before La Liga's transfer window shuts on August 31.
Pogba's reported Barca intentions could alter the approach of United, who had previously been anticipating a choice between player and manager, as it was framed on BBC 5 Live Sport:
Not for the first time, the relationship between Pogba and Mourinho is described as being at an all-time low. Wheeler traced the degradation of their relationship back to last September, when it's alleged the midfielder ignored medical advice to treat a hamstring injury with his own trainer.
The former Juventus talisman was dropped by Mourinho at one point last year and missed out on a starting place in each leg of their UEFA Champions League exit to Sevilla in the round of 16.
TalkSport presenters Alan Brazil and Ally McCoist reacted to Thursday's reports of Pogba's attraction towards the Camp Nou, and the former referred to the 2018 FIFA World Cup winner as "arrogant and aloof":
For all the criticism Mourinho has come in for during his time at United, there have been games that one might have expected Pogba to take by the scruff of the neck, only to fall short. Two years on from spending £89 million to bring their ex-academy star back and United may have expected more.
Wheeler mentioned that Pogba "would have loved" a move to Spain at the time of his transfer back to Old Trafford, but neither Barca nor Real Madrid showed the same interest as United.
Mourinho may not be Pogba's primary cause for wanting to join the Blaugrana, but their declining relationship is unlikely to have helped his ambition to stay.
Goal's Kris Voakes stipulated that harmony between the two would, however, be crucial to the club's success moving forward:
United's inability to sign a replacement means Barcelona are unlikely to complete a signing this summer, but Pogba's motivation to move will give the Catalan giants hopes of renewing their interest in future.