Everton boss Ronald Koeman admits he is still unsure where striker Romelu Lukaku will be playing next season.
Lukaku has scored 25 goals for the Toffees this term and has been linked with a move away from Goodison Park, most frequently to former club Chelsea.
With Koeman recently saying the Belgian did not want to sign a new contract with the club, there has been speculation Everton could cash in this summer.
Koeman, however, says the situation is currently unclear.
He said: "I don't know. We will see what happens at the end of the season."
Speaking at a press conference to preview Sunday's Premier League game against Chelsea, Koeman added: "We like to keep the best players but we know that it is difficult. I don't know if it is possible to keep them at the moment.
"Then we have to analyse the team, (to see) what we need to improve for next season. I think we need, offensive-wise, more players who score more goals because the difference between Lukaku and the rest of the players is too big."
Lukaku will be the focus of a lot of attention this weekend as he comes up against Chelsea.
The 23-year-old joined the London club in 2011 but failed to establish himself and was loaned out to West Brom and Everton before moving to Goodison permanently for £28million three years ago.
Some reports have claimed Chelsea might have to pay a world record £100million to take him back to Stamford Bridge.
Regardless of who the opponents are, Koeman expects Lukaku to want to impress after a disappointing display in last weekend's goalless draw at West Ham.
Asked if playing the Premier League leaders might affect Lukaku negatively, Koeman said: "I don't know. We will see. Normally not. The players always like to show the best of themselves."
Koeman feels there is a collective responsibility for all the players to produce a better performance.
Seventh-placed Everton could clinch a place in the Europa League this weekend - possibly without even kicking a ball if West Brom fail to beat Leicester.
Koeman said: "Maybe we need to change our mentality a bit because I felt a bit less intensity in the game last week, maybe a bit less motivation.
"It is always difficult if you have already the seventh position in the pocket and maybe they get a little bit more holiday or end-of-season feeling.
"That is what I don't like. We like to keep momentum at home, we are strong at home and we know what we need (to do) to face the best team of the Premier League."