He told Sky Sports News: "I haven't had any contact from Everton, I know there's been contact at higher levels.
"I don't know the exact ins and outs of whether there was anything written or anything else but it's irrelevant because he's not for sale.
"Whatever the form of the contact was, we're trying to build a team and we feel that Yakubu is an important part of our team.
"But as I say he is very happy, I have a good relationship with him, he's focused on what he wants to do and he's looking forward to this weekend.
"He's very happy, he's been excellent especially the last couple of weeks as we get towards the start of the season, he's looking sharper and sharper. We're not welcoming any bids particularly 24 hours before the start of the season to take one of our best players away."