I just did a few searches for Johannes Alfray, but came up empty-handed. He's obviously the earliest of the Alfrey line to be recorded, but without the generations between him and John Alfrey (1538), there is no way to establish the link.
I have the same problem in my Wheelock line. The earliest recorded Wheelock is a Hugh de Whelok, who was granted Wheelock Manor by Roger Mainwaring between 1260 and 1280. Unfortunately, no one has the generations after Hugh until the 1400s. Of course, there's nothing anyone can do about it. If the information isn't there, it isn't there.