Everton boss Roberto Martinez has described matchwinner Romelu Lukaku as "irreplaceable".
Lukaku struck the winner against West Ham United on Saturday.
Martinez said: "Lukaku is an irreplaceable footballer and that is a reality.
"There are certain players in certain squads that can't be replaced.
"Barcelona are one of the best teams in the world, but when they have not got Messi the team suffers. You can go on and on and every team has a player like that.
"It is important that he is back and important that he is fresh. This break for him has been perfect. And now he has a clear period of 11 or 12 games with a real freshness about his play.
"He is an important player for us, there is no doubt about it."
