"When you first hear it, you're kind of like, 'What?' " Jennings said Wednesday on NFL Network's "NFL Total Access." "But knowing Brett, knowing the competitive guy he is, he's never going to really give it all up to Aaron. I don't think he should, because I don't think Aaron would give it up to him, trust me."
Jennings then pointed out the Packers' reality since he was drafted in 2006, Favre's second-to-last season with the team.
"We played with Brett, we had success with Brett, we didn't go all the way with Brett, but we did with Aaron, so I think that that kind of speaks for itself."
Jennings also refuted Favre's insinuation that Rodgers simply "fell into" a great situation in Green Bay.
"He took full control of his situation, and that's a credit to him," Jennings said of Rodgers. "He had to sit back, but he didn't just sit back like any other player and just take notes and wonder what he could be doing potentially. He tried to put himself in game mode every week and prepared himself as though he was going to be the starter.
"And I was able to be a part of that for a couple of years, and I saw the way he prepared himself, and ultimately he put himself in a position to be successful once it got to him."