Chelsea caretaker Frank Lampard has admitted Mason Mount is facing the toughest decision of his life.

The attacking midfielder has not agreed a contract with the Blues despite months-long negotiations.

With co-owner Todd Boehly and the club's sporting directors unable to get Mount to agree to a deal, he is likely to be put up for sale when the transfer window opens.

“I think it is a difficult situation," Lampard told Sky Sports.

“From working with Mason and other players when I was here before, they've either gone on to be really important players for the club that have a real relation with the fans, back and forth, because they really feel the club when they've been in the academy since eight years of age.

“And some of them have moved on to other clubs and the club have done well out of that. They've gone on and you've wished them well in their careers.

“I think with Mason particularly, as an individual, I don't know what the solution is going to be because it's a club and Mason issue.

“I don't know exactly where Mason is at personally. He's got a year left on his contract. I know he's held in high regard at the club and I know the club are doing what they can to make him stay.

“But I think also with Mason, I'd never want to stand here and talk in the modern day about what a player should do, because they'll see it all with their own eyes.

“In the old days, it was, "why are you leaving the club?" In the modern day, players move on. It's a shame we've got into a situation where it looks like it's happening maybe now."