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.”
