Harry Kane has been ruled out for between 4 and 6 weeks with a hamstring injury.
The striker picked up the problem in scoring a disallowed goal for Tottenham in their 1-0 defeat at Southampton on New Year's Day.
Kane clutched the back of his left leg in finding the net in 74th minute of the game at St. Mary's.
In theory, Kane's absence could offer a chance to Republic of Ireland teenager Troy Parrott.
However, despite his five-minute cameo against Burnley on December 7 Parrott hasn't been part of Spurs' matchday squad for any of their last four Premier League games.
Kane will definitely miss Tottenham's visit of Liverpool to White Hart Lane on January 11 as well as games with Watford and Norwich City.
Jose Mourinho will hope Kane could return for the February 2 clash with Manchester City but it's feared he could even miss their Champions League last-16 first leg at home to RB Leipzig.
Speaking after the defeat at St. Mary's, Mourinho said of Kane's injury, "Harry is not a machine so sometimes he has to break".
Eric Dier missed the defeat to Southampton due to a virus, but Mourinho hopes to have the midfielder back for their FA Cup 3rd round tie with Tottenham.
Heung Min Son will return from suspension, but Mourinho will be without Tanguy Ndombelé for a spell.
The midfielder was called ashore with an injury after just 25-minutes at St. Mary's, much to the frustration of his manager, "He's always injured. He's injured, he's not injured, he plays one match, next week he's injured, he plays another match. We are full of hopes", Mourinho said after the game.
Mourinho added, "This is it since the beginning of the season. Of course, it is a concern.
"You think you have a good player, you think he is in an evolution process, he plays very well against Norwich, you are full of hopes that today he is ready for it.
"And he is not ready for it. I cannot say much more than that. It's a situation from the beginning of the season."