By Tony Massarotti

In professional sports, the end comes coldly, cruelly, without negotiation. The end approaches. The player resists. But the end still comes.

Peyton Manning is done, folks. He’s been done for a while. The only person who hasn’t really acknowledged this is, as usual, the player himself. In the last several months, there have been a series of explanations and excuses for Manning’s poor play, from a bad quad (last season) to a sore rib (last week) to a bad foot (now). All of them have been a smokescreen for the real problem, which has been apparent for anyone who cared to face the truth, independent of what analysts like Cris Collinsworth tried to feed us a few weeks ago, when Manning had a good night.

Peyton Manning can’t throw anymore, at least not consistently.

And everybody knows it. Deep down, even he knows it.

Sad? Of course it’s sad. At the end, it always is. Whether it be for the money, the fame, the adulation, there just aren’t that many guys out there like Barry Sanders, who leave with their dignity completely intact. Most guys have to be dragged off the stage like some pathetic lounge act, an oversized cane looped around their necks.

“When players get to the end of their careers, they envision something in the way of a parade,” former Red Sox executive and current Chicago Cubs president Theo Epstein once told fading knuckleballer Tim Wakefield. “For most guys, it doesn’t end that way.”

Manning wasn’t most guys during his playing career.

But he is now.

The real story here concerns the thinking of the Broncos, who brought Manning back for 2016, albeit with a pay cut. Were they merely trying to get him the record for most career passing yards? Did they really believe he could help them win? Or did they envision precisely what is happening now, the transition to Brock Osweiler, who will start this week against the Chicago Bears at Soldier Field?

I mean, there had to be a plan, right? John Elway isn’t stupid. And Gary Kubiak had to know what he was walking into. Maybe the Broncos told Manning what their ideas were, maybe they didn’t. But there is no way the Broncos looked at how Manning performed in last year’s postseason against the Indianapolis Colts and concluded that he would return in the fall of 2015 better than ever.

The next question: what is the plan now? When Manning torched the Green Bay Packers on Nov. 1 — he was 21-of-29 for 340 yards and 96.9 rating — he was coming off a bye week. One can only wonder if the additional rest (along with a putrid Packers defensive game plan) factored into his performance. Now the Broncos are giving Manning the week off before the New England Patriots come to town, which can’t help but make one wonder whether the Broncos are implementing a plan to manage their aging, broken-down superstar.

But what if Osweiler plays well against the Bears? Then what? Elway and Kubiak will have to choose between the past and the future, and we all know which side usually wins that one.

Even if Osweiler plays poorly, the outcome for Manning is shaky at best. Patriots head coach Bill Belichick has proven more than a worthy adversary for Manning during his career, particularly at the end. Ditto for New England quarterback Tom Brady. The Patriots are a perfect 9-0 at the moment, despite a rash of recent injuries, and Brady has generally played this season without a hint of slowing down. Now the possessor of four Super Bowl titles — Manning has one — Brady is 11-5 in his career against Manning head-to-head. What was once a meeting of great quarterback minds now looks like an epic mismatch.

The end isn’t near anymore for Peyton Manning.

The end is here.

And if the Broncos haven’t already pulled the plug on him, Bill Belichick and Tom Brady will be reaching for the cord next week.

Tony Massarotti is an avid Boston sports fan and has covered sports in Boston for more than 15 years for both the Boston Herald and Boston Globe. He now serves as a co-host on afternoon drive on 98.5 The Sports Hub in Boston. He was a two-time Massachusetts Sportswriter of the Year as voted by his peers and has written four books, including “Big Papi,” the New York Times-bestselling memoirs of David Ortiz. You can follow Tony @tonymassarotti.

Tony Massarotti