The Scottish star will require an ankle operation after he suffered an injury during their win over San Marino.
"Callum is having an operation on Monday and should be out until pre-season," said the Cardiff manager in his press conference.
"It's a big blow. On the same day [Matthew] Connolly was just coming back training as well and he dislocated his ankle.
"Contrary to what was said before the Scottish game, I never spoke to Alex [McLeish] about him not playing on the plastic pitch [in Kazakhstan]; he's had such a bad injury to his knee in the last 12 months, I think they spoke between themselves.
"But the second game [against San Marino] was a disaster for us."
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