Carlisle trials for Man Utd's Mullan
Nottingham-born Mullan was on the books at Notts County before moving to Old Trafford where he featured in the reserves.
Latterly he was on trial at Leeds and Huddersfield.
Carlisle caretaker manager Greg Abbott said: "We will have a look at him over the next week or so. Then we will see where we go from there."