The full-back has not featured for the Villa Park club this season, and his last domestic appearance came in June during a loan spell at Mallorca in Spain.
But Bannan, who made a switch to Crystal Palace in September after finding first-team chances limited at Villa, believes his fellow Scot is wasted at Villa.
"He's been brilliant," said Bannan. "I found it tough fitness-wise, playing for Scotland when I wasn't involved with my club.
"But Alan's performances have been unbelievable. I can't remember the last time he had a club game - maybe on loan in Spain last season.
"I'd say he's the best right-back at Villa, but I don't know all the ins and outs of what's going on there.
"I'm amazed he's not had a move yet. I'm sure something will come off for him in January, as his form with Scotland has been tremendous."
Scotland welcome the United States to Hampden Park on Friday before meeting Norway on Tuesday.
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