The midfielder's withdrawal in the 48th minute of their 1-0 second-leg win over Rostov in the Europa League round of 16 now puts the Red Devils on high alert.
Manchester United have had 63.7% possession in their home Europa League games this season, the best rate of any side who entered at the group stage.
After a bad-tempered defeat at his old club Chelsea on Monday in the FA Cup quarter-finals, Jose Mourinho has just one more route to silverware left.
United create enough chances this season and Mourinho for the most part this season has set United up in a way that allows them to attack more than one would usually regard a Mourinho team to play but the goals aren't coming.
Anthony Martial was also absent for the FA Cup defeat and his manager has said that he is now "out of his mind" for selection tonight because of a lack of first-team training while recovering.
Mourinho's words came in response to a journalist's question about Pogba's impact on a team that is sixth in the Premier League. One thing is clear: Mourinho and Conte are not friends.
While Sunday's trip to Middlesbrough is their only game remaining before a two-week worldwide break, they are already without the suspended Ander Herrera and Zlatan Ibrahimovic heading to the Riverside. They also played 3 at the back in the first leg as it is their favored system, so Thursday's game will most likely have the same formation.
United were reminded of that fact within minutes of the restart, when Rostov mounted their first unsafe counter of the game.
While the tie appears to remain in the balance, United's lofty reputation and Rostov's own selection problems have prompted visiting manager Ivan Daniliants to adopt a cautious stance.
"Both clubs have their own history, but we are here to make history tomorrow".
"We want to unite and to show a decent performance. We believe in every single player and I am sure that if we do our best the outcome will be positive".
Rostov are without Aleksandr Gatskan and Timofei Kalachev, who are both suspended after being booked last week.
Rostov nearly took a shock lead with their first real chance in the 53rd minute, when Sergio Romero, in only his 10th appearance of the season, was forced into making a fine save from Sardar Azomoun after the forward cut in from the right-hand side and curled a left-foot shoot that was heading for the corner of the net.
Yes - the match will be televised on BT Sport in the UK.