The 25-year old Bayer Leverkusen winger tore his anterior cruciate ligament last month but was defiant when stating he would try and get himself back to full fitness in time for the June kick-off of Brazil 2014.
Kruse was set to be an automatic selection in Postecoglou's Socceroos squad but the manager has urged him not to try and force his rehabilitation for the good of his long-term health.
"Look, he's unlikely to feature," Postecoglou said.
"It's probably going to come on a bit too quickly for him. From our perspective, he's working already hard on his recovery, he's still a young man.
"He's definitely got another World Cup in him. The most important thing is he does his recovery really well and we'll see what happens from there."
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