Manchester United are increasingly concerned about disenchantment with Louis van Gaal's managerial approach among the players and will discuss the situation just before the January transfer window, sources have told ESPN FC.

ESPN FC has been told that some senior members of the squad have even privately complained to club officials about the restrictive style of play and Van Gaal's strict nature.

Recent United briefings to English newspapers had indicated that the club's support for the Dutchman remained emphatic but Old Trafford sources have repeatedly insisted to ESPN FC that was never a unanimous view among club officials, and that some senior figures have doubted him for weeks.

That doubt has only grown in the last nine days, as United were eliminated from the Champions League by Wolfsburg and then lost to Bournemouth to make it five games without a win.

The uncreative nature of the football has been a growing concern, given how little response it is getting from the players. It is not just that United have been failing to win, but they have so rarely looked like winning.

Sources say that even some players who had previously enjoyed Van Gaal's approach, and felt he kept them on their toes in the way Sir Alex Ferguson had, have now completely turned against the former Ajax, Barcelona and Bayern Munich boss.