Spurs duo Victor Wanyama and Moussa Sissoko are now major doubts for the beginning of the new season.
Wanyama missed four months action last season due to a knee injury and he has been instructed to rest again after fears it has returned.
The same knee flared up in training on Tuesday evening and he missed Spurs' 4-1 win over Roma in San Diego on Wednesday but Club officials explained that his absence from the game was precautionary.
According to reports, Wanyama has now flown back to England from US for assessment as his injury crisis deepens.
Speaking after their 5-3 penalty shootout defeat to Barcelona, Tottenham manager Mauricio Pochettino clarified the issues of the two players.
On Wanyama:
“Victor is in London because they need to see the doctor there. Is Victor’s injury the same as before? Yes.”
On Sissoko:
“We will assess Moussa tomorrow and the next few days to see what happens. It is his hamstring but we hope it is a minor injury.”