Carlisle boss Greg Abbott said he hoped to play him in the Darlington game after the week's training ahead of a potential loan move for Long to Brunton Park with their central defender Danny Livesey out injured.
Abbott has now said: "Kevin trained well and he had a good game on Friday night. Overall, all of the trial players who have come into the club this summer have made things hard for us, and that's all you can ask from these lads.
"We now have plenty of thinking to do about them and we'll let everyone know the decision once it is made."