Marouane Fellaini has admitted that tiredness played a part in the defeat at Sunderland that effectively ended Everton's Champions League challenge.
Saturday's 1-0 loss at the Stadium of Light left David Moyes' side six points adrift of the Premier League's top four with only four matches left.
Centre-back Sylvain Distin said after the match that Everton were suffering because they did not have the resources to build a squad that could last the course in a Champions League chase.
And midfielder Fellaini has echoed those views by suggesting that the players have been feeling weary.
The Belgium international, 25, told the Liverpool Echo: "Everybody was perhaps a little bit tired. "It was disappointing for the team and the staff. There weren't a lot of chances.
"Sunderland were playing at home, for a new manager in his first game here. "They had a lot of energy."
Everton host Fulham on Saturday, then visit Liverpool before finishing the season with a home match against West Ham and a trip to Chelsea.
And Fellaini insists that he and his team-mates must keep chasing a place in the Europa League, although they have five points to make up on fifth-placed Tottenham, who have a game in hand.
He added: "We have four more games and we must keep going and try to win.
"It's difficult now but if we try, we will see at the end of the season. We have four more big games – two at home and two away. We will try to win those two at home and we will see where we are after Liverpool and Chelsea."