Both players picked up issues while on international duty. While Netherlands international Kluivert suffered an abductor injury, Gannon-Doak was forced off for Scotland with a hamstring problem.
“I have worries, I have concerns because, as you know, it was a bad international break for us,” Iraola told the media.
“We had confirmed injuries of Justin – an abductor muscle injury – so Justin is going to be out.
“Ben Gannon-Doak has a hamstring injury. Ben’s is a bad one and he will be out for some time. Today, we had a consult with a surgeon to see if it’s something that has to go through surgery, or we could go more conservative.
“Ben will be out for some months, which is really bad news.”
Bournemouth face West Ham at home on Saturday, November 22nd.