The England captain took a knock on his ankle during the game at Wembley and hobbled off the pitch after the final whistle
Mauricio Pochettino admitted Tottenham Hotspur will be in serious trouble if Harry Kane picked up an ankle injury against Manchester United.
The striker was caught accidentally during the closing stages at Wembley, as Spurs searched desperately for an equaliser.
Marcus Rashford scored what proved to be the winner in the first half as United held on to win 1-0, with David De Gea deserving much of the plaudits.
While the result will certainly sting for Spurs, the thought of losing their talisman will terrify the Argentine, who watched helplessly from the sidelines as Kane winced and grimaced on the turf in a heap.
Although the 26-year-old eventually hobbled off the pith without any assistance, Pochettino admitted there was already swelling on his ankle.
“We will assess him,” Tottenham boss Mauricio Pochettino told Sky Sports.
“It was a bad tackle in the last moment. It wasn’t their intention but it was a bad tackle.
“He is a little bit swollen and we need to assess it in the next few days. I hope it is not a big issue.
“It is worrying because we are going to lose [Heung-Min] Son to the Asian Cup, and if Harry Kane suffers some issue it is going to be a massive problem.”