Paul Parry is expected to miss Wales' World Cup double-header with England and Poland next week.
The Cardiff winger will meet up with the squad on Monday, but Bluebirds boss Dave Jones says he is not fit to play.
"He's got a knee ligament problem and once the Wales medical team see that they will send him back," said Jones.
Boss John Toshack is already without defenders Mark Delaney, Danny Collins and striker Craig Bellamy, while James Collins is rated as very doubtful.
West Ham centre back Collins has yet to play a game this season because of a calf injury.
Toshack is also upset that defender Rob Edwards is being allowed to play for Wolves at Molineux on Tuesday.
Edwards, or Coventry youngster Richard Duffy, will replace Delaney at right-back in Saturday's match with England in Cardiff and against Poland four days later in Warsaw.
The Football Association of Wales asked for Edwards to be withdrawn from club duty, but their request was turned down by world football's governing body Fifa.
"We understood there was a four day rule for players to be released from their clubs - or 96 hours before kick-off," complained Toshack.
"That would mean from three o'clock on the Tuesday afternoon, but maybe the rules are different if you play for Brazil and not Wales, I'm not sure.
"Hopefully Rob Edwards will join us after the game on Tuesday evening which means I wouldn't expect him to participate too much on Wednesday
Wales are also without left-back Ben Thatcher for the England match as he serves the final game of his three-match suspension.
In better news, John Hartson scored his seventh Celtic goal this season in their 4-0 win over Dunfermline on Sunday.
And captain Ryan Giggs was selected for his first Premiership game for Manchester United this season, although he stayed on the bench in the 2-0 win at Newcastle.
But unlike England manager Sven-Goran Eriksson whose Premiership stars will not be action, Toshack faces a worrying time on Monday when his Football League players play again for their clubs.
"Maybe 30 or 35% of our squad will be involved on Monday afternoon so it's probably going to be Wednesday afternoon before we really see the fitness levels of the players we've got," said Toshack.
"There's not much we can do but just wait and keep our fingers crossed."
Wales squad to play England in Cardiff on 3 September and Poland in Warsaw on 7 September:
Coyne (Burnley), Jones (Wolves), Price (Ipswich), J Collins (West Ham), Duffy (Portsmouth), Edwards (Wolves), Gabbidon (West Ham), Page (Coventry), Partridge (Bristol City), Ricketts (Swansea), Roberts (Tranmere), Thatcher (Man City), Davies (Everton), Fletcher (West Ham), Koumas (West Brom), Parry (Cardiff), Robinson (Sunderland), Vaughan (Crewe), Williams (West Ham), Earnshaw (West Brom), Giggs (Man Utd), Hartson (Celtic).