Carlos Cuellar is doubtful for Rangers' Uefa Cup tie against Sporting Lisbon.
The Spanish defender is struggling with a virus ahead of Thursday's quarter-final second leg tie.
Gers boss Walter Smith is sweating over the availability of Cuellar with defensive partner David Weir missing the trip to Portugal because of suspension.
Worry"We have told him to stay at home in the hope that he can shake things off before we travel out to Portugal on Wednesday," Smith told the Scottish Daily Express.
"At this stage he is rated as doubtful, which would give us a few problems to contend with as Weir isn't available.
"Both he and Davie Weir have been the cornerstone of our defence all season so it would be a massive setback and disruption if both were to miss the Sporting tie."