Manchester United boss Louis van Gaal says he has been "very bored" during some games this season.
"There are matches that I have enjoyed," said the Dutchman.
"And there are also matches where I'm very bored or angry because we are not disorganising our opponent's defence, but that is football."
Van Gaal's team were booed off at half-time during Saturday's FA Cup win over Sheffield United, with thousands of home fans leaving early.
Asked why many fans had left before Wayne Rooney's 93rd-minute penalty secured a 1-0 win, Van Gaal replied: "They are not thinking that we would score, I think, and maybe also because of the traffic."
Van Gaal suggested United fans should be "happy" with their team's current form, despite the fact that they failed to register a shot on target until the 69th minute against their League One opponents.
United travel to the Championship's second-placed side Derby County in the fourth round, but return to Premier League action on Tuesday, when they face struggling Newcastle United at St James' Park.
Van Gaal's side are fifth in the table, nine points adrift of leaders Arsenal and three behind fourth-placed Tottenham, with 18 games left.
'There's no smiling'
Paul Scholes is one of several ex-United players to criticise United's style of play and attitude.
The 11-time Premier League winner says the players and manager looked "bored" and claims there is "no spirit".
"There's nobody having a go at each other, there's no smiling, there's no entertainment," said the midfielder.
"Even Van Gaal looks bored, but he'll come out and say he's happy."
'I'm not Sir Alex'
Van Gaal has defended accusations that he is not vocal enough on the sidelines, rejecting comparisons with former boss Sir Alex Ferguson, the club's most successful ever manager.
"I'm not Sir Alex, as you know," he said,
"Everybody is different and I don't believe in yelling from the sidelines.
"I believe in communication during the week, during the preparation and I believe in my players who have to perform."
The former Barcelona and Bayern Munich boss claimed a lot of managers yell from the sidelines but added: "I doubt if they have real influence."