Hull had agreed a £5million deal with Fulham last month for Zamora, but failed to agree a deal with player.
“Fulham have advised us that he is no longer available,” Duffen told the Hull Daily Mail.
“It’s not disappointing, it’s just a fact that we’ve got many, many targets.
“We’ve moved on and we’re still confident of signing the strikers that will improve us.
“It’s never disappointing to lose out on someone who doesn’t show any passion for a move.”
