Paul Pogba will surely be considered as a major injury doubt for Manchester United's Premier League meeting with Swansea City on Sunday (6 November) after sustaining an injury during a demoralising 2-1 Europa League loss to Fenerbahce.

The world's most expensive footballer started the Group A tie in Istanbul, but was caught by a poor challenge in the first half and began limping heavily with what appeared to be a dead before being replaced by Zlatan Ibrahimovic with only 30 minutes on the clock. United's midfield options for that forthcoming trip to south Wales have already been depleted with Ander Herrera set to serve a one-match suspension after being harshly sent off for two bookable offences in last weekend's goalless draw with Burnley.

United were caught cold by a stunning overhead kick from Moussa Sow inside two minutes against Fenerbahce and fell further behind shortly after the hour mark when Sunderland loanee Jeremain Lens beat David de Gea with a perfectly-struck free-kick.

The visitors dominated possession for the most part and set up a grandstand finish when much-maligned captain Wayne Rooney drew level with Ruud van Nistelrooy as the club's all-time top European goal scorer, although an irate Jose Mourinho did not believe his side deserved anything from the game.

Paul Pogba
Paul Pogba limped off after half an hour of Manchester United's defeat to Fenerbahce STRINGER/AFP/Getty Images

"I think they deserved to win," he told BT Sport after the full-time whistle. "Football is not just about quality, it's also about effort and commitment. It's about playing the limits and giving everything, so I think they deserve [it]. A team that concedes a goal after two minutes is a team that is not ready. It's a team that is not mentally prepared, not focused, not concentrated.

"In an atmosphere like this, to concede a goal and give the advantage to the opponent... Then the opponent is where they want to be. Then they defend, then they counter-attack, then they stop the game, then they simulate free-kicks and put pressure on the referee's decisions. They win lots of time with injuries. But it's their game."

United travelled to the atmospheric Ulker Stadium missing three first-choice defenders through injury in Eric Bailly (knee), Chris Smalling (foot) and Antonio Valencia (fractured arm) and the manager was evidently unimpressed with the makeshift centre-back partnership between Marcos Rojo and Daley Blind as well as the intensity of his team.

"They were playing the Champions League final and we were playing a summer friendly, " he added. "That is the reality of the way the game started. After that obviously we had moments of reaction, but I think it's difficult for us to play a game of this difficulty with two left-backs playing central defender. I think it's not possible to be really dominant and strong without two strong central defenders."

Thursday night's contest also saw an overdue return to United duty for Henrikh Mkhitaryan, who was introduced with just under 30 minutes left to play. The £26.3m ($32.7m) summer signing has not even been deemed worthy of a place on the substitute's bench for the last six matches since returning from a recurring thigh strain and Mourinho has now publicly challenged the Armenian to improve.

"He has to do more. It's as simple as that. We have big expectations in the club."