Jordan said: "AJ signed a five-year contract last summer but circumstances change.
"He's a great player but we're not a one-man team and I will do what I think is best for him and the club. If I do sell it will be at a price that suits me and not the buyer.
"I think he's worth £20m but I'm in a minority of one. We've already had bids from Wigan, Everton and Bolton plus there's been interest from other clubs.
"Bolton offered the most at £8m but he will go on the monetary terms we agree and we're looking at double figures.
"AJ's a proven goalscorer and would grace any team, including England."
Johnson, 25, left England training early yesterday for crisis talks with his chairman.
And Jordan admitted: "We've got a mutual respect and I asked to see AJ to talk about the situation. I need to discuss my thought process and also see what he wants to do.
"But he needs to understand how this will play out.
"If he is to be sold it will happen quickly. But until someone puts an offer in front of me that I like, he'll stay at Palace."