DISCIPULUS: GESTA ROMANORUM

DISCIPULUS MEDICI / ADULESCENS: ACCORDING TO THE GESTA ROMANORUM

[···] a pupil of the physician, a young man, but possessing the wisdom of old age [···]

What's more, Cerimon approves of him (called merely "the youth" and "the young man") like this:

"I approve your skill", returned he, "I magnify your art, and wonder at your prudence. 
Mark the results of learning, and be not ungrateful to science. Receive now thy reward [···]"

A footnote calls him: [···] this same wise youth [···]