The Buttfumble is behind him, in the rearview mirror, but a world of uncertainty greeted Mark Sanchez when he walked back into the Atlantic Health Jets Training Center yesterday as the tarnished Golden Boy, his Jets career hanging by a thread, viewed more now by a team that once heralded him as its franchise quarterback as an $8.25 million albatross it cannot hope to ship to Tampa in the looming Darrelle Revis trade.

It was a good day for Revis, getting a green light to begin running on his surgically-repaired left knee — ostensibly to the Tampa Bay Independence Bank — and a good day for Sanchez in that he didn’t find the locks changed on him when he showed up.

Because it isn’t his team anymore, and it isn’t his job anymore for the first time since he arrived in 2009. His buddy Dustin Keller is a Dolphin, Rex Ryan is a lame duck, Santonio Holmes is nowhere in sight, Marty Mornhinweg will be his third offensive coordinator in three years, Revis is on his way out the door, an unforgiving fan base in a town without pity will be waiting in ambush ... and yet Sanchez wouldn’t want a fresh start, an escape from New York, as much as Tim Tebow does.

Not to mention the possibility that if and when general manager John Idzik pulls the trigger on the Revis deal between now and next Thursday’s NFL draft, the Jets, armed with two first-round picks, might be tempted to select Geno Smith, E.J. Manuel or Ryan Nassib to join David Garrard, Greg McElroy and Matt Simms in the full-fledged summer quarterback duel.

And yet, here comes Sanchez, battered and bleeding the last time we saw him, spoiling for the fight of his life, announcing “BRING IT ON!” loud enough to hear without a green-and-white megaphone.

“My heart and soul is into this thing,” Sanchez said. “I’m fired up about this year and hope it’s a good one.”

Back to the future, when he was the talk of this town.