The right-back, impressing in his breakthrough campaign with the Blues, appeared to pick up an ankle injury following a collision with Ciaran Clark.
James, 20, was wincing in pain on the ground as he received treatment.
It quickly became clear he couldn't continue and was replaced for the final 15 minutes by Emerson.
James did manage to limp off down the tunnel without the aid of the physio to receive a further diagnosis of his injury.
Isaac Hayden swooped for a late winner for the Toon.