Tottenham boss Harry Redknapp fears midfielder Steven Pienaar may have suffered a groin tear during the 2-1 friendly win over Athletic Bilbao.
The 29-year-old South African was going to see a specialist after the game to check the extent of the injury.
Redknapp said on Saturday: "Steven Pienaar picked up an injury today. He might have torn his groin. I think we're going to take him to a specialist and have a look at him. We'll see how it goes."
If a tear is confirmed, Pienaar would almost certainly be ruled out of Tottenham's opening Premier League game against his former club Everton next weekend.
Goals from Peter Crouch and Jermain Defoe secured victory for Tottenham in their last friendly match before the new season.
Meanwhile, Redknapp thinks Tottenham's financial limitations will rule them out of the Premier League title race.
Spurs have been surprisingly quiet in the transfer window and are battling to keep Luka Modric from moving to Chelsea.
Redknapp wants to strengthen his team, but he has had to watch the likes of Manchester City and Liverpool spend multi-million pound fees on their summer recruits.
Manchester United boss Sir Alex Ferguson admitted this weekend his side face a tough challenge in defending their title as a result, but did not list Tottenham as contenders.
And manager Redknapp said in The Daily Star Sunday: "If you want to be a top-four side, it's difficult because we can't pay those kind of wages.
"Fergie didn't mention us when he spoke of title contenders and it's looking that way."