Tottenham manager Mauricio Pochettino is concerned defender Jan Vertonghen sustained a "bad" injury in the 4-0 win over West Brom at White Hart Lane.
The central defender, 29, appeared to be in tears after turning his left ankle after half-time.
"We need to wait for tomorrow and Monday to assess him better. It looks bad," said Pochettino.
"He is disappointed and in a very difficult period but we will push him to recover quickly to try to help him."
Vertonghen has played 20 of Tottenham's 21 league matches this season, forming part of a defence which has conceded just 14 goals - the best record in the league.