Tottenham head coach Thomas Frank says the injury suffered by midfielder James Maddison during Sunday's pre-season draw against Newcastle "looks bad".
The former Leicester City playmaker, 28, pulled up off the ball seven minutes from time during Spurs' 1-1 draw with the Magpies.
The England international looked in clear discomfort and had to be stretchered off from the field of play, while team-mate Son Heung-min, during his final appearance for the club, was visibly emotional watching on.
Frank says Maddison, who missed the Europa League final victory against Manchester United last season with a knee injury, has likely injured the same knee.