There was speculation the England international, last season's Premier League top scorer, could face two months on the sidelines.
"I always try to be honest with you. Just half an hour ago we received the report about the scan and it's much, much better than we expected," Pochettino told reporters.
"Maybe we can reduce the time (that he is out) but we are happy, the scan was very positive, we are very happy about this news but still we cannot give a time for how long his recovery will be," the Argentine added.
"We are happy because the scan was better than we expected. I am not a doctor, it's difficult to say how long but it's true that it's much, much, much better than what we expected and that is very positive."
Tottenham face Russian side CSKA Moscow in Champions League Group E on Tuesday.
(Reporting by Nivedita Shankar in Bengaluru, editing by Ed Osmond)
