The 29-year-old former Real Madrid star left the field in tears with a leg injury during United’s 1-1 draw against Chelsea last Saturday.
“Varane is not in the selection,” Ten Hag said at a press conference on the eve of United’s Europa League match with Moldovan sheriff Tiraspol.
“He will be out until the World Cup. We have to wait and see how he develops, how his rehabilitation will develop.”
Varane, who has suffered multiple long-term injuries during his career, is aggravating French coach Didier Deschamps’ headache before designating his roster for the final in Qatar on Nov. 9.
N’Golo Kante, the Chelsea defensive midfielder who was a key part of France’s success four years ago, is sure to miss the tournament with a hamstring injury.
Paul Pogba is in doubt as he is still recovering from knee surgery and AC Milan goalkeeper Mike Maignan, the backup to first-choice Hugo Lloris, could be ruled out with a calf injury.
France’s first group match at the World Cup is against Australia on November 22, against Denmark on November 26 and Tunisia four days later.
Ten Hag said Cristiano Ronaldo would be in the roster for Thursday’s game – a match his side must win to stand a chance of surpassing their group.
That would allow them to avoid a third-place finish from the Champions League in the February play-off round.
Ronaldo returned to first-team training at Manchester United on Tuesday for the first time since refusing to substitute against Tottenham last week.
The Portuguese was excluded from United’s squad for Saturday’s 1-1 draw at Chelsea and trained individually with fitness coaches on Friday.
“It is not difficult (Ronaldo situation). We have said everything, answered all questions. He was out for one game and now back in,” said Ten Hag.
“We have an important game tomorrow, we want to be at the top of the group.”