Jose Mourinho says he believed Manchester United "were always in control" before Feyenoord struck a surprise winner in their Europa League opener on Tuesday.
After beginning the game with a much-changed lineup, Mourinho put on Zlatan Ibrahimovic, Memphis Depay and Ashley Young in the 63rd minute in an effort to win the game.
But the tables were turned when Tonny Vilhena scored the decisive goal for the Eredivisie side in the 79th minute, leaving Mourinho frustrated.
"Of course I'm unhappy. We lose the game in a moment we didn't deserve to," the manager told BT Sport.