As Jene said, it looks like it's going to be Kiel and McCree.
McCree will start at one safety spot. The battle is really between Kiel at SS (in which case McCree would play FS) and Jue at FS (in which case McCree would play SS).
Kiel has been working with the first team all through camp, and the reports I've seen all say that he is playing well.
One thing to keep in mind, though, is that DB coach Brian Stewart really likes Jue. Last year, it was generally acknowledged (by the players and by the assistant DB coach, Albert Lewis, who has since been let go) that Jerry Wilson had outplayed Jue during camp last year, but Stewart still went with Jue as the starter.
So there's still an outside chance that you'll see a McCree-Jue combo at safety, but a Kiel-McCree combo must be considered the favorite at this point.