The Japan defender has hurt his knee ligaments in training and is highly unlikely to figure again for the remainder of the season.
"It is true he will be out for six or seven weeks but his participation in the World Cup will not be threatened," assured Pochettino.
"It will be difficult for him to play in the last six weeks of this season."
He added: "I actually went through a similar situation in a World Cup and I had a similar injury to his but I recovered a month before and was able to take part in the World Cup.
"He has started working already this week so he shouldn't miss any training sessions and the staff and all of us are going to help him so that's back to his best as soon as possible."
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