Cape Town - David Moyes has categorically ruled out the sale of striker Jermain Defoe during the January transfer window.
The 34-year-old, who is a reported target for West Ham, has scored eight goals this term.
Moyes feels the club's survival could centre around making sure Defoe remains happy and keeps scoring.
Speaking ahead of facing Manchester United on Boxing day, Moyes said: "He's priceless, isn't he? There is not a price we could put on his head because he's so important to us staying as a Premier League club.
"He's scored us eight goals just now and if he scores us another eight or 10 in the second half of the season, it will give us a great opportunity of staying up."
He added: "We won't sell him, but we obviously can't stop people talking about it and writing about it."
Defoe's relationship with Victor Anichebe is another positive for the club, with Moyes insisting their bond is proving key to their good form.
He added: "Victor's form has been incredible. I don't think you could put a value on what Victor's worth at the moment for us, the way he has played.
"I don't know how much it would cost us to go out on the high street and try to buy a Victor Anichebe somewhere, but it would be a lot of money."