WATCH: Linesman somehow fails to spot offside in Feyenoord’s winner against Manchester United

The first Europa League group match in the history of Manchester United didn't exactly go to plan, as Jose Mourinho's men lost 1-0 to Feyenoord.

In truth, the goal came as a bit of a surprise. With nearly 80 minutes played, chances had been sparse in Rotterdam. What wasn't that much of a surprise was that when the goal *did* come, it was the result of a mistake from Marcos Rojo. The Argentine, making his first appearance of the season for United had frequently been caught out by Feyenoord as he pushed forward down the United left, leaving Chris Smalling - also making his first start of the campaign - exposed at the back. Having pushed forward once more, the defender missed out on a challenge leaving a Feyenoord midfielder with the simple task of sliding the ball through to a teammate. Incredibly, despite standing yards away, the referee failed to spot that the pass's recipient was clearly offside, leaving him to cross the ball to Tonny Vilhena to slide home the winner. https://twitter.com/bl3palos2/status/776490666381627392 https://twitter.com/btsportfootball/status/776491299432177666 United will now face Zorya in their next Europa League outing on September 29. The Ukranian side narrowly missed out on a victory over Fenerbahce after conceding an equaliser deep into stoppage time. Stephen Rochford chats with Colm Parkinson on The GAA Hour, heated Lee Keegan debate, and Barry Cahill is outnumbered by Mayo backers. Subscribe here on iTunes.