Craig Bryson, Chris Burke, Kevin Thomson and Lee Wallace were added to Gordon Strachan's squad following the withdrawal of West Brom midfield duo James Morrison and Graham Dorrans on Sunday.
Scotland assistant McGhee added Hull player to that list.
He said: "George Boyd has gone home. He has had some sort of ankle injury I think.
"We know about James and Graham, they are a big loss, both of them, but we brought in other and we are getting on with it.
"Quite a few of them didn't train today but we are expecting a full complement tomorrow."