Everton manager Carlo Ancelotti admits he needs to use the summer transfer window to make the necessary adjustments to weaknesses in his squad.
The Italian has been left frustrated by inconsistencies in performances which has seen them swing from good to bad depending on whether they are playing away or at Goodison Park.
Everton have the fourth-best away record in the Premier League heading into the weekend, with only Manchester City, Manchester United and Leicester better.
At home, however, it is a different matter as they are 15th in the form table having taken just 19 points from a possible 51.
Ancelotti will not admit it publicly but he knows some of the players he inherited from predecessor Marco Silva 17 months ago are not up to the task.
"Of course, we have to analyse the season and after that put the right adjustment in the squad to avoid the limits and the weakness we have had this season," he said.
He still has five matches remaining in the current season though, only two of which are at Goodison, and he remains optimistic he can get enough out of the players to secure qualification for European football.
Sunday's opponents West Ham, just three points behind fourth-placed Chelsea, have shown what can be done with more consistency, and Ancelotti has to find a way of getting some short-term gain in the next month.
"It is a vital game against West Ham. They are in a better position than us at the moment," he added.
"We don't have a lot of possibility but we want to put all our energy into a game we can consider vital for the end of the season.
"We are frustrated about the performance against Aston Villa (a 2-1 home defeat last weekend)
"All the time you have problems you have to move on, move forward, to give confidence to players after a bad performance, a defeat.
"Usually the history of this season says after all the time we had problems we have moved on with a fantastic result. There are a lot of examples.
"At the start of the season we had problems against Southampton and Newcastle and injuries but then we were able to beat Chelsea.
"At the same time we lost at home to Fulham and one week later we won the derby."
