Donald Faison went NUCLEAR on the streets of NYC over the Giants benching Eli Manning ... saying it's "the most disrespectful thing" he's seen in his whole damn life.
TMZ Sports spoke with Turk about the Giants news ... and simply mentioning Eli led him to shout at the top of his lungs: "That's some BS, yo! Everybody's saying it!! BS!!! IT REALLY IS BS!!!!"
Donald -- who loves the G-Men -- says he's got a good reason to be pissed considering all Eli's done for the franchise.