Brett Favre is an expert on rocket arms, durability streaks and awkward quarterback changes.

Favre infamously cold-shouldered Aaron Rodgers for three years before the Green Bay Packers decided it was Rodgers’ time and traded an unretired Favre to the Jets in 2008.

But Favre is enshrined in the Hall of Fame and Rodgers will join him in Canton one day — and the Giants can only hope to be so lucky that Daniel Jones will replicate Eli Manning’s career as a two-time Super Bowl MVP.

As for right now? Manning is trying to be the good mentor — even though he admits he never felt it part of his job description when he was starting — as he watched Jones light it up Sunday in his first career start.

What was Manning thinking after Jones led the Giants back from an 18-point deficit and became the first rookie quarterback ever with at least 300 passing yards, two passing touchdowns and two rushing touchdowns in a game since 1970?

Manning didn’t speak to reporters afterward and he probably would’ve said the right thing, as he usually does.

“You and I and anyone else can only speculate what Eli was thinking," Favre said on his weekly Sirius XM NFL Radio program, “but you have to think that deep down inside a part of him, not wanted to see Daniel Jones fail but not play at the level he did.”

Favre says it’s human nature to protect your own self-interest even while rooting for teammates.

“Not that Eli has to prove anything to anyone,” Favre said. "The short-term it really makes you look bad. And all the things that have been leading to the team’s losses falls back on you — and you know that’s not the case. It’s hard to say, ‘Heck, I guess it’s me. I guess the reason we are losing these games is because of me.’ You have to believe that at some point that crosses his mind.”

If so, Manning did a good job hiding it. He stayed out of the spotlight before, during and after the game, only offering Jones words of encouragement or tips where appropriate. Manning spent Sunday on the sideline wearing a baseball cap and an earpiece. When the game was over, the quarterbacks hugged.

“I think he has seen the writing on the wall before this last game. If anything it has solidified what we thought was coming anyway,” Favre said. "The Eli Era, at least with the Giants, is over.

"But Daniel Jones did exactly what he needed to do. He did exactly what they had hoped he would do given that opportunity. … The kid played great and did a heck of a job in a lot of different ways. Really, from a debut standpoint, it couldn’t have gone any better.”

The Favre-led 2008 Jets started 8-3 but finished 9-7 and missed the playoffs.

Giants general manager Dave Gettleman joked about using the Green Bay model and keeping Jones on the bench behind Manning for three years. Instead, Manning lost his starting job two games into his 16th season, after a sixth 0-2 start in the last seven years.

Jones stepped into the shoes of replacing a legend, in a road game, for an impatient fan base.

“It was a different debut than most because of all the circumstances which you just alluded to,” Favre said. "That is a tremendous amount of pressure, as if it wasn’t a lot of pressure to begin with.

“And the fact that he is replacing, I think, a future Hall of Famer in a hostile environment — and I’m talking about really from your own fans, the expectation level is always at an all-time high in New York. And the patience level is at a very low standard with the fans there. They expect it now. And he delivered."

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Jones will make his second career start — first at home — Sunday against the winless Washington Redskins.

“I think what really impressed me throughout the entire game was his poise,” Favre said. "He played as if that was his 50th start, and just seemed calm and cool and collected in every phase and at every point during the game.”

Ryan Dunleavy may be reached at rdunleavy@njadvancemedia.com. Follow him on Twitter @rydunleavy. Find our Giants coverage on Facebook.