Tottenham striker Kane diagnosed with hamstring tear
Harry Kane has suffered a tear in his left hamstring, but Tottenham have given no indication how long the striker will be out for.
The England captain will definitely miss Sunday's FA Cup trip to Middlesbrough while the club's medical staff "continue to review the injury with treatment ongoing".
Kane, who limped out of Spurs' defeat at Southampton on New Year's Day, tweeted on Friday afternoon: "Head up. Tough times don't last, tough people do."
Tottenham head coach Jose Mourinho was fearing the worst over Kane's condition in a press conference earlier on Friday.
The Portuguese said: "I don't know yet, maybe later today we have news but if you ask me just my feeling – good news or bad news – I am more on bad news than good news, that's my feeling.
"What the player felt, Harry Kane leaving a match, the way he did it, he didn't think twice, it didn't take him two seconds to realise the severity of the situation.
"Some opinions from the medical department before the test results. I don't think we're going to have good news.
"But the reason we're here is because of the beautiful FA Cup and in relation to that we can say that no Middlesbrough for Harry Kane."
The loss of Kane will undoubtedly be a big blow for Spurs, who are just beginning to stutter under Mourinho after an initial bounce following his appointment.
Kane has scored 27 goals in 31 appearances for club and country this season, but Mourinho is not prepared to dwell on it.
"I'm great on experience and feelings, and again I'm not expecting very good news," he added.
"I think we're going to lose him for some period and because I am totally convinced of that I can anticipate that, I don't want to sit here with you crying in every press conference now.
"Everybody knows who he is, what he is, what he means for the team, the fans, the club.
"His quality, the routines that the team has playing with him, every minute of every game he doesn't play we miss, so every match that he doesn't play we're going to miss him.
"But I don't want to be crying here all the time, I want to focus now on the players that are available.
"Now Son (Heung-min) is back I prefer to speak about Son than Harry."
Son will be available at Middlesbrough and is likely to lead the line, with Lucas Moura or 17-year-old Troy Parrott also possible options.
While he could feature at the Riverside Stadium, Mourinho does not see Parrott as an immediate replacement for Kane.
"I think too soon. I think one thing is potential and another thing is conditions to express potential and I think he needs time," Mourinho said.
"Having minutes, being involved is one thing. Another thing is what you call the direct replacement.
"To be that he needs to work. There are many different processes of a player to develop.
"The next step for him is to sign a new contract at the club long-term and then it is for everyone to decide what is the best for his development.
"In this club we care about our players. It is also to find the best pathway to develop."
Another player who will be at The Riverside Stadium is Christian Eriksen, even though his future is unclear.
Eriksen is now free to discuss a move with European clubs while he might also be sold, after telling Spurs he will not be signing a new contract.
The only thing that Mourinho can guarantee is that Eriksen will be involved at Boro.
"I don't know and I am being honest," he said when asked about his future. "You know the situation, in this moment he can agree with any club for the end of the season. That is one option.
"Another option is a club and himself want to do a deal in January, but in that situation our club is in control.
"We have the control of the situation. Another possibility is he stays. In this moment he is here, he is our player.
"I can say Harry Kane and (Tanguy) Ndombele will not be at Middlesbrough, I can say Christian Eriksen will be at Middlesbrough."