Jose Mourinho admitted striker Harry Kane's injury is as bad as he feared after seeing Tottenham held to a 1-1 FA Cup third round draw at Middlesbrough.

Kane damaged a hamstring in the 1-0 Premier League defeat at Southampton on New Year's Day and although his manager does not yet know how long the England captain will be sidelined, it appears he could face an extended spell out.

Mourinho said: "I think it is better for the medical department to speak about it or make an official report.

"The only thing that I can add is that the feelings I had that it was not a small injury were correct. It is not a small injury, but I cannot speak about times."

Kane's absence was noticeable as Spurs struggled to break down a well-organised Boro at the Riverside Stadium, with Son Heung-min and Lucas Moura attempting to plug the gap.

It was Moura who eventually cancelled out Ashley Fletcher's 50th-minute opener with a firm header, but the Portuguese was disappointed his side did not make more of their share of possession, although he refused to use Kane's misfortune as an excuse.