Middlesbrough right-back Tony McMahon is facing a spell on the sidelines with a stress fracture of his foot.
The 23-year-old has been hampered by a foot problem for some time and has continued to play, only for a scan to resolve the issue.
Boss Gordon Strachan told the Evening Gazette: "It's a blow for Tony and another blow for the squad but now we know what we're dealing with."
He added: "You wonder when it is all going to come to an end. In the last three months we have had one injury after another.
"It doesn't help you trying to put a run of results together when you are making changes from one match to the next."
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