The England international was his side's star player in his side's 4-1 win over Liverpool at Wembley. He scored a brace as the north London club sealed a comfortable victory and was withdrawn in the 88th minute.
Kane was seen leaving the field clutching his hamstring. Mauricio Pochettino hinted the 24-year-old could be doubtful for United clash after he saw his side crash out of the Carabao Cup following Spurs' 3-2 defeat to West Ham United.
According to the Sun, Tottenham have admitted that Kane did strain a hamstring against Liverpool. The striker now remains doubtful when they take on Jose Mourinho's men on Saturday.
Pochettino rested Kane for the Carabao Cup fixture against the Hammers. The Argentine coach had earlier played down any injury concerns after his side's victory over the Merseyside club in the last league tie.
The former Southampton manager has the services of summer signing Fernando Llorente as the second choice striker in the squad. Should Kane fail to make himself available for United clash, the Spaniard is likely to be given a chance against the Red Devils.
Kane could face a late fitness test, if he travels with the squad to Manchester. It should be seen whether Pochettino is ready to risk his striker as Spurs have two big fixtures ahead of them. They face Real Madrid in the Champions League, four days after United clash.
His absence will be a massive blow for Tottenham as Kane has been in fine form this season. He scored 13 goals in 12 appearances in all competitions, which includes five goals in the Champions League.