Tottenham suffered a potentially serious setback as Gareth Bale was stretchered off with an ankle injury in the final moments of Thursday's 2-2 draw against FC Basel in the Europa League quarter-final first leg.
Bale, who has been in superb form this season, clutched his leg in agony after being stepped on by David Degen in stoppage-time at White Hart Lane and was eventually carried down the tunnel for further treatment.
If Bale, scorer of 27 goals for club and country this term, is sidelined for a lengthy period it would be a huge blow for Tottenham, who are battling to qualifying for next season's Champions League via a top four finish in the Premier League.
Andre Villas-Boas's team are currently third and face a crucial clash against Everton on Sunday.
Bale's injury capped a frustrating evening for Spurs, who had to settle for a draw after falling two goals behind following a poor start against the Swiss champions.
Valentin Stocker opened the scoring after 30 minutes and Fabian Frei headed home the second five minutes later.
Togo striker Emmanuel Adebayor reduced the deficit from close-range five minutes before half-time and Gylfi Sigurdsson's deflected 58th minute strike drew Spurs level.