Everton manager Carlo Ancelotti expects Richarlison to work harder to drag himself out of his current slump.
The Brazil international has scored just one goal in his last 12 Premier League matches and has only six for the season, two of which came against League One Fleetwood in the Carabao Cup.
A sending-off in the Merseyside derby in October resulted in a three-match ban and further disruption and he has not been able to recover the form which saw him score 15 times last season.
Richarlison spent more time on the floor having been fouled, or thinking he had been fouled, in the 2-0 home defeat to Newcastle than he did threatening the opposition defence and Ancelotti wants him to put in extra effort to turn around his fortunes.
"He has to be more focused, he has to sacrifice more and that is it. There is no other way that I know to improve," said the Italian.
"I think he is not in a good moment because the statistics talk. It is true that he was suspended for three matches and he had difficulties to reach his best level.
"I hope that he can reach his best level with sacrificing more and more focus. Work harder on the pitch. Harder.
"He is working hard on the pitch and working hard in training. He has to understand what he is doing. I think he works hard every day. He has to work harder."
Everton, too, have struggled to regain their early consistency which saw them win their first seven matches in all competitions in their best start to a season in more than a century.
Four successive league victories in December, after one win in their previous seven, suggested they were back on form but they have picked up three points in only one of the last four league matches and dropped eight points at home to West Ham, Leicester and Newcastle.
"We are not the only team who are up and down," added Ancelotti, who labelled the performance against Newcastle as "lazy, slow and not focused".
"I was a little bit surprised because in the last period we showed good consistency, good spirit.
"How can we keep this? By working day by day on this. There is no other way, but we have to understand that this season is really peculiar."