Rangers centre-back Marvin Andrews could miss Trinidad and Tobago's second match of the World Cup finals against England on Thursday.
Marvin Andrews (right) was injured during training
The 30-year-old suffered a recurrence of a knee injury in training and was ruled out of Saturday's opening game against Sweden.
Coach Leo Beenhakker said: "He is injured and for sure will not make it."
After a scan, doctors said it would be 24 to 48 hours before they could determine how long Andrews will be out.
Andrews, previously of Raith Rovers and Livingston, played on this season after refusing an operation on a cruciate ligament injury picked up in March 2005.
His latest setback means Beenhakker, who had last week questioned the player's fitness, will have to reshape his defence.
He is a very strong guy, a very important guy for the team
Trinidad & Tobago coach Leo Beenhakker
Andrews had forged a partnership with Wrexham's Dennis Lawrence, one of the main reasons why Trinidad went from being outsiders to securing a place in the finals.
Former Dundee defender Brent Sancho or Gillingham team-mate Ian Cox could be the Rangers man's replacement.
"The injury happened when he stepped a little bit wrong in training," said Beenhakker.
"It is a little bit of a problem as Marvin was playing on a certain level for Glasgow Rangers.
"He has international experience as well as Champions League experience.
"He is a very strong guy, a very important guy for the team, but we have to accept the situation.
"Injuries are part and parcel of football. You hear about it all the time.
"After playing in all the qualifying matches, Marvin is very unlucky."
Meanwhile, there is also an injury doubt over Dundee goalkeeper Kelvin Jack, who could lose his place to West Ham United's Shaka Hislop against Sweden.
And veteran Falkirk playmaker Russell Latapy appears likely to be held on reserve on the bench.