Robson said: "Robbie's got a slight little knee injury at the moment but nothing serious and we're in the beginnings of negotiations about him with Nottingham Forest,"
"It could be resolved early next week because the closure of the transfer window on Sunday doesn't affect First Division clubs."
Forest manager Paul Hart is looking for more squad depth and played Wes Morgan as left-back against Norwich even though he is naturally right-footed.
It is believed a loan deal is most likely even though Robson would prefer a permanent move.
Forest's only other left backs are Davy Oyen, who is struggling to hold down a first-team place, and Gregor Robertson, who is inexperienced and prefers to play more central.
Elliott, who once made two England U21 appearances, has played a total of 143 games for Newcastle and has scored 10 goals.