There are always exceptions. Nothing is impossible. But the odds are not good that a cornerback who runs a 4.64 is going to become a quality starter in the NFL. In fact, the odds are not good that he’ll stick on the 53-man roster at all, at least not as a boundary corner.Jerry Rice ran a 4.7, and later was very competitive in the NFL's Fastest Man races. The utility of the athletic testing is to try to determine if it matches what you see, and revisit your evaluation if it doesn't. And if your evaluation is based on 40 time, you are missing some significant data points. It's also fair to question whether Johnson was completely healthy when he ran his 40, and whether he looks like a 4.64 guy in pads, because that's the only time it matters. From what I've seen, the main thing working against him is his age.
I’m no psychic. We’ll see. I’m not optimistic.