The breathtaking dismantlement of the 49ers is almost complete, and NFL free agency hasn’t even started yet.

It’s as if Jed York is the owner from the movie “Major League,” except he already has the new stadium.

If Niners fans thought letting Jim Harbaugh walk was the low point of what has become their Offseason From Hell, the run-up to Tuesday afternoon’s start of free agency has been an even colder bucket of ice being dumped on their head.

In the wake of Monday’s twin retirement announcements by Patrick Willis and Justin Smith, just three of San Francisco’s 11 defensive starters in the Super Bowl three years ago are expected back this season — Aldon Smith, Ahmad Brooks and NaVorro Bowman.

And that’s just on one side of the ball. Also expected to depart in free agency are workhorse running back Frank Gore (Eagles or Colts), wide receiver Michael Crabtree and one of the best guards in the game, Mike Iupati (a Jets target reportedly headed to the Cardinals).

If York, the Niners’ wildly overmatched, 36-year-old frontman for owner/parents John and Denise DeBartolo York, thinks signing Torrey Smith, Darnell Dockett, Jerome Simpson and a football novice from Australia are going to quiet the panic about his cratering franchise, he’s already wildly mistaken.

The pessimism is so rampant in the Bay Area that York found himself Monday having to deny publicly rumors that he is looking to trade quarterback Colin Kaepernick.

York shouldn’t have been surprised. When you push out the popular coach who took your downtrodden team to a Super Bowl and two NFC Championship games in just four years as coach because you didn’t like his abrasive personality, anything seems possible.

The Eagles pulled off a surprise Monday by re-signing linebacker (and Giants target) Brandon Graham, but questions persist about the secret grand plan Chip Kelly continues to roll out this offseason.

Fresh off winning his power battle with former GM Howie Roseman, Kelly has wasted no time in revamping a roster that wasn’t exactly barren of talent last season.

True, the Eagles missed the playoffs in Kelly’s second year as coach after winning the NFC East in 2013. But it’s still causing indigestion in Philadelphia to see a 1,300-yard rusher in LeSean McCoy get traded to the Bills and a 1,300-yard receiver in Jeremy Maclin be allowed to bolt — reportedly to Andy Reid and the Chiefs — in free agency.

Kelly also cut serviceable veterans Trent Cole, Carey Williams, Todd Herremans and James Casey, and the only newcomers identified so far are injury-prone linebacker Kiko Alonso and (soon-to-be wildly overpaid) cornerback Byron Maxwell.

Kelly was on the verge of signing Gore, who at 31 is five years older than the running back he would have been replacing, but Gore reportedly had second thoughts Monday and could be headed to the Colts instead.

Kelly also is thought to be shopping quarterback Nick Foles and strongly interested in moving up in the draft to take former Oregon pupil Marcus Mariota, even if doing so will require mortgaging the Eagles’ draft future.

Kelly had better be right with this plan, because the fallout will be ugly otherwise.

The three-day “negotiating window” before the start of free agency quickly became a farce over the weekend when deals involving Ndamukong Suh and others were leaked.

Since teams technically weren’t allowed to talk money with imminent free agents, the NFL responded Monday with a sternly worded email to all clubs promising investigations into the deals and potential penalties for conduct detrimental to the league.

No one is expecting the league to follow through, of course. The “violations” were too widespread and would be too difficult to verify, and many team executives think the NFL all along expected handshake deals to emerge from the period.