Tottenham defender Jan Vertonghen could be out for a considerable length of time after he limped off tearfully during the 4-0 Premier League win over West Brom.
Vertonghen turned his ankle painfully when chasing a ball towards the touchline and immediately showed distress.
The 29-year-old Belgium international was ruled out of his country's Euro 2016 quarter-final defeat to Wales with ankle ligament damage but returned to start the Premier League season with Spurs.
The only match he has missed so far in the top flight this term was at Watford on New Year's Day through suspension, but boss Mauricio Pochettino now looks set to have to do without one of his defensive mainstays for the trip to Manchester City next weekend and beyond.
"Yes it looks very bad. We feel very disappointed," Pochettino said at a post-match news conference, before confirming Tottenham must wait for Vertonghen's swelling to subside in order to fully survey the damage.
"It looks very bad but we need to wait and assess him on Monday or Tuesday."
Even if Vertonghen does prove to be a long-term absentee, Pochettino insisted he will not be forced into the January transfer market for a replacement.
"No - no change," he said. "We have Ben Davies, Kevin Wimmer has played against Watford and Aston Villa. We have plenty of players.
"We won't need another centre-back."
Vertonghen's anguish took some of the shine off a majestic Spurs display, with Harry Kane's hat-trick pushing them up to second in the Premier League table - four points behind Chelsea ahead of the leaders' trip to face champions Leicester City.
"I'm very proud. The effort was amazing and fantastic. We played wonderful football," Pochettino said.
"The way we played they could not compete with us. We have learned a lot and matured since last season."