Tottenham boss Mauricio Pochettino fears Harry Kane may have suffered a similar injury to the knock that left him sidelined for two months earlier this season.
Kane hobbled off after appearing to twist his ankle awkwardly during a challenge five minutes into Spurs’ 6-0 FA Cup sixth round victory over Millwall at White Hart Lane.
Tottenham’s top scorer suffered an injury to the same ankle during a game against Sunderland in September, which kept him out of action for seven weeks.
Pochettino said it was too early to assess how serious the injury was, although Kane now looked likely to miss Spurs’ game next Sunday with Southampton.
He added: “He twisted his ankle, it is the same ankle that he injured before in the game against Sunderland.
“Now we have to wait and assess tomorrow, or the day after tomorrow, and see but today it is difficult to say, it looks like a similar situation to the Sunderland game.
“Today it is too difficult to give a real level of how his ankle is, we hope it is not a big issue but it does look similar if you watch the replays.
“I think it will be difficult for him to play against Southampton on Sunday but we need to wait now and see what happens in the next few days.”
Tottenham were able to make do without Kane’s talents, putting six past their League One opponents in a dominant performance to book their place in the FA Cup semi-final draw.
Christian Eriksen opened the scoring before Son Heung-Min, playing as a centre forward in Kane's absence, bagged a hat-trick.
Dele Alli got himself on the scoresheet in the second half, while goal-shy striker Vincent Janssen came off the bench to grab his first from open play in a Spurs shirt.
Pochettino said: “When you lose a player like Harry Kane, you will miss him, but it is important for the players who can play in his position like, Son and Janssen, to find the back of the net.
“We have talked in the past about the squad and how all the players are important. Sometimes people criticise the manager when we rotate the team.
“Now look what has happened, now in the last two months of the season you need your key players for every team.
“Players like Janssen or Son, maybe they have not played in the last few weeks in the starting eleven, but now they will be important for us.”
Spurs will find out tomorrow evening who they will play at Wembley next month as they aim to reach the FA Cup final for the first time since 1991.