Tottenham manager Jose Mourinho has said he is expecting "bad news" regarding the extent of Harry Kane's hamstring injury.
Spurs released a statement on Friday which said the striker suffered a tear in his left hamstring during the 1-0 defeat to Southampton but did not confirm when he will return.
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"We can confirm that Harry Kane suffered a tear in his left hamstring during our New Year's Day fixture against Southampton," the statement read.
"Our medical staff will continue to review the injury with treatment ongoing."
The club also said the Spurs captain will not feature in the FA Cup clash against Middlesbrough on Sunday.
When Mourinho was asked about the extent of the striker's injury at a news conference, he replied: "I don't know yet, I think maybe later today we have news.
"But if you ask me just my feeling, good news or bad news, I am more bad news than good news, what the player felt, Harry Kane leaving a match the way he did.
"He didn't think twice, didn't take him two seconds to realise the severity of the situation."
Tanguy Ndombele and Danny Rose will also miss the FA Cup tie through injury but Son Heung-Min is available after serving his three match ban for a red card against Chelsea last month.
Spurs have lost four of their last eight matches in all competitions but Mourinho is relaxed about the club's situation and sees similarities to when Jurgen Klopp took charge of Liverpool in 2015.
"The end of this season is not the end of the world," he added. "Klopp arrived in October 2015, eight transfer windows, lots of players coming and going, and lots of time for him to get across his philosophy, training methods, his fingerprints.
"In the first season they finished sixth or eighth and four years later they are the best team in the world. So no panic, calm. I have lots of experience, the club has lots of experience, Mr Levy has lots of experience.
"But I don't want to compare us with Liverpool, I just want to ask for calm. Some teams are at the end of a cycle, some are in a transition, some are at the start. These are different scenarios."