I broke the end on the hard drive, I had all the pieces, I put it together and used hot glue to keep the cable in place. I have not had any issues with the drive for at least 3 years and I moved over 1500 miles with it in the case.
As long as it can make contact with the cable and can see the drive you will no problem. It can not cause any harm if it is seen and does not get banged around. If you move the computer a lot it could cause a problem of coming loose.