“It was no performance from us – it was a bad performance,” he said at his post-match press conference. “We didn’t play, we didn’t compete and we made it easy for Everton. It was a bad team performance.
“This is the first game I have had a bad feeling about the way we performed. The performance today was nothing [compared] to the games since I’ve been at the club.
“Today we let ourselves down because we didn’t compete against Everton, and they won all the first and second balls. They played to compete and we were second best in every department.
“In the end, we got what we deserved.”
Despite the result, Vieira said that Palace were determined to find consistency and supported the character of his players.
“We may have to set-up in a different way, but I don’t want to change our principles,” he said. “At times [this season] we played well and did not have a chance to get what we deserve.
“Overall this game doesn’t reflect the other games we played away from home, because we are missing everything in our game today.
“I never question the attitude of the players. I work every day with them, I know what they are doing and that is why it is important to remain calm.
“One of the areas that we need to improve is how can we be more consistent in our performances. Again, today was a bad day but I will not question the attitude or the quality of the squad we have.”