Don't expect to see Darren Waller on an NFL field ever again ... the former Giants star tells TMZ Sports he's thrilled with his decision to retire -- and is adamant he'll feel that way going forward.
The ex-tight end officially called it a career on Sunday ... but at 31 years old and still productive when healthy, many of his fans wondered if he really meant it.
But, when we spoke with him a couple days after he made the choice to hang up his spikes, he made it clear, he's done done.