Ronald Koeman is giving Ross Barkley an ultimatum that he must sign an extension with Everton or leave the club.

"We offer him a new contract, and then [there are] two possibilities," he said when asked what he could do to keep Barkley. "One, he signs that contract, if he doesn't sign that contract then we need to sell the player. It's simple, it's not so difficult in my opinion."

Romelu Lukaku's future at Everton is also uncertain but Koeman is determined to fight in order to keep his star men.

"We try to keep the best players," Koeman added. "We spoke a lot about Ross and Rom because they are really important. Most of the time the quality of the players can be the difference between Everton and the opponent, and they played really well.

"We know Rom is a great finisher but Ross played really good football between the lines. I think he should have scored one but it is what you like to see -- your best players performing like they showed because they played outstanding, the whole team performance was outstanding.

"You need those kind of players on their top level because they make differences and that's what we like."