Paul Pogba admitted he and his Manchester United team-mates did not have the right attitude during the humbling defeat to Brighton on Sunday.
The Seagulls led 3-1 at half-time thanks to goals from Glenn Murray, Shane Duffy and Pascal Gross.
Pogba got a goal back in injury-time but time ran out for Manchester United, who suffered defeat at Brighton for the second consecutive season.
Speaking to Sky Sports after the game, Pogba said he and his team-mates did not approach the game in the right way.
My attitude was not right. It has to be a big lesson for us, the World Cup winner said.
They had more hunger than us. I put myself first, that my attitude wasnt right enough. We made mistakes we shouldnt make.
We tried to push and push, we kept trying, but it was a bit too late.
We were playing at home last week and thats different. Different teams, different tactics. I know you cannot always play very very good.
The attitude always has to be very good and we missed that.
Brighton manager Chris Hughton, speaking to BBC Sport, said: I thought we were very good today. A victory we deserved.
Theres not a player that didnt play well. To get that result with the quality they have you have to put in a good performance.
We wanted a reaction from last week. Today was about getting the ball and not allowing them to get the ball to dictate the tempo. Over 90 minutes there werent clear chances they had.