alright, here's what i found:
http://www.mcsweeneys.net/letters/earlyjan00.html
Date: Mon, 10 Jan 2000
From: SK
Subject: Parcells' Nickname
Dear McSweeney's,
Ann Courgage wished to know the origins of Bill Parcells' nickname "The Tuna." Very well: when Parcells was linebackers' coach for the New England Patriots back in 1980, during a rather strenuous drill one of his charges complained that he (the player) was injured or sick or something, so that he could no longer continue. Parcells snarled back, "That's bullshit! Whaddaya think, I'm that gullible? I ain't Charlie the Tuna!!" referring of course to the hapless Star-Kist pitchfish who's always foiled in his attempts to get himself canned. (As opposed to Parcells, master of the strategic resignation, who always leaves on his own terms.)
I must leave it to others to decide whether this bit of backstory is germane to the poetic analysis in question, however, for I am afraid any criticism I offer may reveal more about my disdain for the Tuna himself than actual insight into the poem's meaning. Recusingly,
Sean Kelley
Somerville, MA