Jose Mourinho fears Harry Kane could be out for "a few weeks" after the Tottenham captain injured both ankles in a 3-1 Premier League defeat to Liverpool on Thursday.
England striker Kane did not return for the second half at Tottenham Hotspur Stadium after requiring treatment twice in the opening 45 minutes.
Kane has been struck with ankle problems in the past and although Mourinho was unsure over the extent of the damage his talisman sustained, the Spurs boss is braced for having to cope without him in the short term at least.
Asked about Kane's injuries, the Portuguese told Match of the Day: "Two ankles, the first was a bad tackle, it was Thiago [Alcantara]. The second one I didn't know well.
"But two injuries in both ankles, the second one worst than the first one – a few weeks [out], I don't know.
"There are some players you can't replace. When it happens it happens but I believe we have to fight against it, we cannot do anything else."
Spurs face Brighton and Hove Albion on Sunday before taking on Chelsea in a London derby, then face clashes with Everton and Manchester City before coming up against Wolfsberger over two legs in the UEFA Europa League next month.
Their eight-match unbeaten run in all competitions was brought to a juddering halt by champions Liverpool, who rediscovered their goalscoring touch with strikes from Roberto Firmino, Trent Alexander-Arnold and Sadio Mane.
Pierre-Emile Hojbjerg had made it 2-1 with a stunning first goal for Spurs after Alexander-Arnold capitalised on a mistake from Hugo Lloris early in the second half.
Son Heung-min had an early goal disallowed for offside after Mane missed a glorious early chance to open the scoring and Mourinho felt Tottenham only had themselves to blame for a defeat that leaves them eight points behind leaders City in sixth place.
"My analysis is that we started very well, but before we scored the offside goal we showed immediately what the game was going to be for us – a big occasion for Mane, a big defensive mistake," he said.
"That was the game for us, the team in the first half was very well organised, the goal is another mistake in the same position.
"The second half we had to make changes, we lose Harry, had to change the structure of the team. First minute, same mistake, second goal. Good reaction, another mistake and goal.
"It was a team fighting against its own mistakes. Some individual mistakes that you saw, you can replay and I cannot say much more than that."