Gareth Bale will have a scan on his ankle injury on Friday as Tottenham wait to discover how long they will be without the Welsh star.
Bale was stretchered off in the closing moments of Tottenham's 2-2 draw against FC Basel in the Europa League quarter-final first leg at White Hart Lane on Thursday.
The Wales winger had clutched his leg in agony after Basel's David Degen stood on his right ankle, with pictures of the incident showing Bale's foot bent into an unnatural position.
Spurs manager Andre Villas-Boas admitted after the match that Bale would definitely miss Sunday's Premier League clash with Everton.
Bale has been in the form of his life this season, scoring 27 goals for club and country, and his absence for a prolonged period would be a major blow to Tottenham's bid to qualify for the Champions League.
Spurs are currently third in the Premier League, two points ahead of fourth placed Chelsea.
But Villas-Boas, who also lost Aaron Lennon and William Gallas to injury on Thursday, is keeping his fingers crossed that Bale could be back to face Manchester City on April 21, providing the results of a scan are positive.
"There is lots of swelling and the pain is obviously very, very big," Villas-Boas said after the Basel match.
"There is a big possibility he is going to be able to make it for the Man City game and he will only miss the next two games, but we can only give you that assurance tomorrow (Friday).
"Gareth will definitely play again this season. From the medical department's first analysis, everything is positive.
"It shouldn't be as bad as it looks because Gareth has torn that ligament before and there's nothing to tear now."