Everton manager Ronald Koeman has admitted that it will take more than one season for the club to establish themselves as top-four contenders.

The Toffees have lost just one of their last 11 Premier League games to move within two points of sixth-placed Manchester United, with Koeman repeatedly insisting that his side can finish in the top six this season.

However, their hopes of further progress suffered a blow earlier this week when star striker Romelu Lukaku admitted that he is considering leaving the club due to a lack of ambition.

"Every player likes to play for titles, in the Champions League - that is a normal ambition," Koeman told reporters.

"What we need to do and like to do is show everyone that if there is one club outside of the big six to make the next step, then it is Everton. I think it is impossible to do this in one transfer window, in one season. It takes time.

"That is a message for everybody. The manager every day is trying to get the best and strongest team we can have. It is not only money, it is about showing players they see ambition and the development of the team and the club is progressing."

Lukaku, who is the Premier League's joint leading goalscorer with 19 this season, had been expected to sign a new five-year deal at Goodison Park before his recent U-turn.