Burnley defender Michael Keane feels they let themselves down in defeat at Crystal Palace.
The Clarets blew a two goal lead to lose 3-2.
"We need to learn our lessons," admitted former Manchester United defender Keane.
"We are normally solid at the back but we weren't ourselves and got punished. We've got a couple of weeks to get over it and make sure we are ready to go for Sunderland. Our squad is not short of character."