The 30-year-old twisted his left ankle during Sunday’s win at West Brom and was sent for scans on Monday after pulling out of the England squad to face Brazil on Wednesday.
Spurs manager Andre Villas-Boas expects Defoe to return within three weeks but there are fears he could face a lengthy period on the sidelines if he has suffered extensive ligament damage.
Tottenham is currently fourth in the Premier League as it chases a place in next season’s Champions League - but it is short of strikers after failing to land Brazil international Leandro Damiao during the January transfer window.
Emmanuel Adebayor is the only fit senior striker at the club and is expected to return to the side for the clash against Newcastle on Saturday after Togo was knocked out of the African Cup of Nations at the weekend.
Spurs recalled youngster Harry Kane from a loan spell at Norwich but the Londoners will hope for positive news when they receive Defoe’s scan results on Tuesday.
"Defoe means a lot to us as a team, as a person and as a player,” said Villas-Boas after his side’s 1-0 victory at the Hawthorns. “He has been withdrawn from the England squad. He has rolled his ankle. We have to scan to make sure what the extent of the injury is. Hopefully there is not a lot of ligament damage. If there is, it could be up to two or three weeks to recover.
"I have no regrets [about not signing a striker]. Obviously we took the risk because we felt we had options. We are not far from Adebayor being back. Still, we are safe with the options we have. We create a lot as a team. Our goals come from different sources and once again Bale has done the business. He is having a great season."