Girardi has called him "Janko" in nearly ever article I've read over the past two weeks. Chooch, J-Roll, Cutch - everyday player nicknames are just part of the game, as is fans presuming that familiarity. (I also find it tolerable from the not-objective announcers, but hate when they use first names).
Obscure list acronyms, OTOH, could probably use a glossary, especially if they are exclusive to the list (there probably already is one for the ones that aren't, i.e. LOOGY, TNSAAPP).
Still not entirely sure why Cutch is "Uncle Larry" though.