De Jong has successfully made his return to Barcelona's first team after overcoming a lengthy injury setback.
Asked about an Oranje recall, Koeman said: “I spoke on the phone last week and, with all due respect, he is still too far away. He played a little and just that was scary for him. It was difficult for him.
“Frenkie needs to find his rhythm and be in 100% shape and I think he still has some to go for that."
De Jong was back for Barca in last week's Champions League win against Young Boys after an ankle injury first suffered in April.