Manchester United crushing defeat at the hands of Athletic Bilbao has left Sir Alex Ferguson questioning his own methods, as his side's Europa League hopes hang by a thread.
The Basque side outplayed United for long periods at Old Trafford, with Wayne Rooney's goals working as scant reply to a polished display from the La Liga side.
Fernando Llorente, Oscar de Marcos and Iker Muniain struck to leave United staring down the barrel of a second exit from European competition this season, with Ferguson ready to change tact.
"I think there’s been that slackness all season [with defending]," he told MUTV.
"And, but for David De Gea, we could have lost by four or five goals. He was absolutely superb.
"We’ve had a bad season in Europe, it has to be said. We’ve lost three goals against Basel, two against Benfica, two to Ajax and three tonight. That tells the story.
"Maybe it's just one of these years when we need to take stock in terms of assessing how we should approach games at home."
After picking up just a single win in their three Champions League group games, United have lost both of their home games in the Europa League, against Ajax and Bilbao.
Ferguson had tended to rest many of his established stars in Europe this season, with Rio Ferdinand and Michael Carrick, two of those to miss out from the start on Thursday evening.
The 70-year-old had previously stated his team selection had proven crucial in the club's previous failures on the continent, and admits juggling his squad ahead of the second leg will be crucial to securing their progress.
"I’m going to need to assess our games because we’re maybe finding it difficult to marry the two competitions together, playing Thursdays and Sundays as we do normally with the Champions League," added Ferguson.
"I think we can win the game okay.
"I made the point during the week that we’re now starting to get players back. To marry the two together successfully, I think you need the full squad.
"We tried to make the changes tonight to freshen up, particularly midfield, as best we could. We certainly could do with all the players back to marry the two together."