Christie has been training with United for a couple of weeks and was due to be offered a short-term deal but then he picked up a back injury.
The deal was put on hold but Dennis Wise plans to sit down with the former Middlesbrough player once the injury clears up, which is expected to be in about 10 days time.
The 28-year-old was released from Boro last summer after an injury-hit four years on Teesside.
Wise said: "I do need another striker. That's the department I'm after just to give us a bit more of a threat."