Wales could be without any recognised left-backs for Thursday’s friendly with Northern Ireland in Cardiff.
Tottenham’s Ben Davies has been ruled out with a head injury sustained in Spurs’ Europa League loss to Borussia Dortmund, though he is expected to return for Monday’s game in Ukraine.
Neil Taylor missed Swansea City’s 1-0 win over Aston Villa because of a dead leg and is also rated as doubtful.
Forward Hal Robson-Kanu has been ruled out of both Wales’ March warm-up games.
The Reading player was unable to train on Tuesday due to a leg injury, despite linking up with the rest of the national squad.
The 26-year-old was injured in the first half of Saturday’s 1-1 draw against Cardiff and has now returned to his club.
Chris Coleman’s side face Northern Ireland on Thursday at the Cardiff City Stadium, before facing Ukraine away, four days later.
Forward Gareth Bale has been left out of the squad in a joint decision between the Football Association of Wales and his club Real Madrid.
Wales are also without Aaron Ramsey, James Collins, Andy King and David Edwards through injury and illness.
Another left-back option, Newcastle’s Paul Dummett, was not named in the original squad after suffering a setback in his return from a hamstring injury.
Walsall forward Tom Bradshaw also misses the game with Northern Ireland through injury, but Chris Coleman expects him to return for the Ukraine match.