It gets increasingly difficult to guess which player or even which position a team will go with at the back-end of the first round of the NFL Draft. When it comes to the Detroit Lions, most have went ahead and done it anyway, pegging them as likely to take a cornerback, as the team doesn't really have any starters at the position currently on the roster. It just so happens that one of those cornerbacks, Janoris Jenkins, has some other issues that are making his stock plummet, so many consider the Lions a likely team to jump on him and his potential.
Todd McShay didn't seem to think the Lions would go with a cornerback in his latest mock, as noted already. He had them go with Whitney Mercilus, a defensive end, which almost seems excessive at this point, given their defensive line. Detroit would be spending an awful lot of picks on defensive linemen altogether, and their weakness in that vein is stopping the run, which isn't something Mercilus is built for.
That being said, McShay did address the cornerback position in the second round. He mocked UCF cornerback Josh Robinson to Detroit at pick No. 54 in the second round. With Eric Wright leaving for free agency and some injury-prone safeties, Detroit really does need the help in their secondary, and will likely address the position in one of the top two rounds.