Tottenham fans will fear the worst after Harry Kane was forced off in the opening minutes of their FA Cup quarter-final against Milllwall, leaving Spurs without their star striker and top scorer.

The 23-year-old has continued his excellent form in the Premier League this season, and leads the way for Spurs with 23 goals in all competitions the help lift the side to second in the table.

However, Spurs manager Mauricio Pochettino had reason to be concerned within minutes of kick-off at White Hart Lane on Sunday as Kane went down injured following a shot at goal from a narrow angle near the Millwall goal.

After having his shot saved by Millwall goalkeeper Tom King, Kane was caught by defender Jake Cooper and twisted his left ankle under the weight of the 22-year-old. The injury appeared to be to the same ankle that Kane injured earlier in the season September last year that kept him out of eight games, including the international break with England.

After receiving treatment for a number of minutes, Kane was not able to continue and limped back to the Tottenham dugout and straight down the tunnel, shaking his head as he passed manager Mauricio Pochettino.

Speaking after the match, Pochettino did little to ease the fears that the injury may be a repeat of the one he suffered earlier in the season, and if faced with a similar time out on the sidelines, Kane may not play against this season.

"He twists his ankle - the same ankle as it was before against Sunderland. Now we will wait and assess tomorrow and wait and see," Pochettino said.

Kane's ankle was trapped under the leg of Millwall defender Jake Cooper (Getty)

"Today it's difficult. It's a similar situation to Sunderland. We need to assess him today it is difficult to give you a real level of how he is.

"We hope it's not a big issue but it looks similar. It's sure it will be difficult for him to play against Southampton but we need to see what happens in the next few days.

Kane needed treatment before limping down the tunnel (Getty)

"Every time something like this happens and before the scan he immobilises with a [protective] boot."

The Argentina chose against sending on replacement striker Vincent Janssen, and instead replaced Kane with attacking midfielder Christian Eriksen, meaning that Son Heung-min switched to a central role to lead the attack with Dele Alli behind him for support.

The loss of Kane could have a huge impact on Spurs's season (Getty)

Kane shook his head when speaking to Tottenham manager Mauricio Pochettino (Getty)

The sight of Kane being forced off will not only concern Spurs supporters, given they have struggled to find a consistent goal scorer away from the striker this season, but also for England fans with the international break just two weeks away where England will face Germany in an international friendly and Lithuania in a World Cup qualifier.