Brett Hundley wasn't sad at all about being traded from Green Bay ... in fact, dude was jacked up about the move to the Seahawks -- his dad tells TMZ Sports.
"He was just at a point where he was ready to start anew somewhere else," Brett Hundley Sr. says.
"I mean he was very, very excited."
Don't get it twisted ... Brett -- who was traded Wednesday -- says the QB loved his time with the Packers and learned a lot from Aaron Rodgers -- but he tells us playing behind Russell Wilson will be awesome.
"I'm sure Russell's going to welcome him with open arms," Brett Sr. says.
"And Brett's going in with the mindset that, 'Hey, I'm just going to be here, compete and do everything that I can to help this organization and franchise.'"
By the way ... Brett Sr. says the family predicted a trade from Green Bay was coming -- but they thought it'd be a Bay Area team that got the QB -- until Seattle made the bigger push.