Ronald Koeman has confirmed that Everton are in talks with Romelu Lukaku over a new contract but admits the striker may not stay at Goodison Park in the long-term.
Lukaku's agent, Mino Raiola, said on Wednesday that a new deal for the Belgian international was "99.9 per cent" done but stressed a new contract would not prevent him leaving at the end of the season. Lukaku's current Everton deal expires in 2019.
Sky sources understand that the deal is not quite as close to being finalised as that but Koeman admitted he understands the "business" side of fresh contracts for players and said it is never certain they will always see out their new deals.
"I know they are in talks together about a new contract but, if it is 99 per cent, I need to believe his agent," he said. "It's a big deal and that is what the club is showing to keep the best players and do everything to keep them in the club because that is the future.
"Of course you don't know in football what can happen in one year but at least there is understanding and the boy likes to stay and he is a big part of the Everton future.
"They [players] sign new contracts but don't say they will stay until the end of the contract. That's football, that's business, we will see. But I think first if the new deal is done then that's good news."
Lukaku joined Everton from Chelsea for a club-record £28m in 2014 and has scored 70 goals in 142 appearances.