Manchester United manager Louis van Gaal accepted the club's fans had every right to be critical after seeing their side suffer a shock 2-1 Europa League defeat at Midtjylland.
The travelling supporters - who in the build-up to the game hit out at the high ticket prices - voiced their displeasure as Pione Sisto and Ebere Paul Onuachu sealed a famous win for the Danish champions after Memphis Depay's scrambled opener in the first leg of the last-32 tie.
The loss piles further pressure on Van Gaal's precarious position at Old Trafford and the Dutchman understands why United fans are upset.
"They are disappointed like we are disappointed," said the Dutchman after United suffered a second successive 2-1 defeat following a setback at Premier League strugglers Sunderland on Saturday.
"The fans can criticise. They can do it.
"When you see the second half, maybe they are right, but we have to improve and then those fans will support us again. We have seen that in the 18 months I have been here.
"I'm very grateful for the fans supporting us. They want to win like we want to win, and we hope that at Old Trafford we will do it [in the second leg]."
Van Gaal denied United's problems are down to the mindset of his players, as he said: "It is nothing to do with attitude.
"All of the players want to perform in an excellent way so attitude is not the case.
"We were not winning the second balls. That is my analysis."
On Midtjylland substitute Onuachu, Van Gaal said: "We had a lot of difficulty with him and we have to cope better with that problem, then maybe he shall play at Old Trafford and we have to cope with that problem."