Nick Bosa tried it first, taking a few steps after his game-ending sack of Case Keenum, belly-flopping to the FedEx Field turf and gliding on his chest along the sopping grass. A few defensive teammates joined immediately. As the clock neared zeros, Bosa’s San Francisco 49ers teammates streamed from the sideline in a wave, sprinting a couple of yards, diving and then hydroplaning, turning Daniel Snyder’s soaked, sullen stadium into their personal Slip ’N Slide.

“Like a bunch of little kids out there,” 49ers defensive lineman DeForest Buckner said.

The Washington Redskins could only watch, their dreary, 9-0 defeat ending with their opponents’ swaggering flourishes. In the other locker room, Coach Kyle Shanahan announced he would give a game ball to his father, Mike, whom Snyder fired in 2013 after a tenure in which the two men frequently clashed. Washington had hung with the undefeated 49ers but never seriously threatened an upset. As hearty fans trudged mercifully for the exits, the Redskins couldn’t even muster anger at the 49ers’ celebration.

“Winning cures everything,” guard Ereck Flowers said. “If we’d have won the game, there wouldn’t be no sliding.”

It was another bleak Sunday in a long string of bleakness. The shutout offered more evidence — needless at this point — that Washington’s season is lost and that the remaining 10 weeks matter only in how they can enhance Washington’s future prospects.

That’s a dicey topic of discussion to begin with, because the only consistent thing about Snyder’s 20 years, particularly during the past 10 with Bruce Allen as a top executive, has been the snuffing out of any signs of promise. But if you’re a fan of the franchise and haven’t given up hope yet, the only point of this season is the future. Washington has not acted as if it realizes that fact, and it needs to.

Whether Jay Gruden was at fault or blameless for the ruinous beginning of Washington’s season, his firing two weeks ago should have resolved a central problem to this Redskins season. They had a lame-duck coach with no incentive to develop players or plan for the future. The best course of action for today was inherently at odds with the best course of action for tomorrow. That was untenable to begin with because of the presence of first-round quarterback Dwayne Haskins, and it grew even more untenable when losses mounted and their season spiraled before October.

Without the man in charge coaching for his job, Washington had a chance to reset its priorities. Under interim coach Bill Callahan, all indications are they have not. Callahan’s outlook, and his first two games, have suggested the coach has changed, but the core present-vs.-future problem remains.

In his opening news conference, Callahan declared himself a devotee of the running game who would work tirelessly with the sole aim of winning games, and his actions have validated those promises. Nobody could blame Callahan for doing his job that way, but they run counter to what Washington needs now. And if he doesn’t amend his approach, his bosses ought to do it for him.

Washington threw only 12 passes Sunday as journeyman Case Keenum took every snap. The Redskins ran the ball on their first 10 snaps, leaning heavily on Hall of Fame-bound Adrian Peterson. They added a fullback, Michael Burton, to the roster this week and used him frequently as an effective lead blocker.

What does that accomplish? What is the point of lining up Peterson in the I-formation and pounding the rock while Keenum flails and Haskins watches?

With the caveat that a victory Sunday would have put them only two games out of first place in the underwhelming NFC East, the Redskins’ season is dead. They can use these games to find and develop players who could be useful in coming years. On this roster, that means promising young wide receivers and Haskins. It means giving offensive coordinator Kevin O’Connell, viewed internally as an up-and-comer, a chance to call plays unencumbered by offensive thinking out of step with basic modern tenets.

To be fair, Sunday presented Callahan with challenging conditions. Playing Haskins against San Francisco’s fearsome pass rush in the slop would have amounted to sabotage. The cold rain and wind forced Callahan to run even more than he wanted.

“The conditions played into the decision to run the ball a little bit more and be more controlled in the pass and limit the pass attempts,” Callahan said. “That was more for field conditions and weather conditions. We wanted some more attempts.”

That’s fair. The problem is, Callahan does not seem intent on playing Haskins. Callahan gave Haskins more practice reps in his first week, and this week, with Keenum nursing a foot injury, Haskins took the majority of the first-team snaps. That is a good first step. But it would be a mistake not to give Haskins game experience and learn more about what exactly the Redskins have in him. Callahan seems to be leaning toward making that mistake.

“Dwayne’s still learning,” Callahan said. “I think he’d be the first one to tell you that. We still have faith in Case and his ability to manage this offense and run this offense. We’re moving forward with Case at this juncture.”

In discussing Haskins, Callahan struck the same notes as Gruden. It’s past time to let Haskins prove, on the field, whether he is ready. Maybe it would be irresponsible to give Haskins his first start Thursday night on the road, after a short week and against Kirk Cousins, the quarterback Washington let walk in free agency and somebody natural to measure Haskins against. Fine. Washington’s following game is at Buffalo 10 days later. Callahan should use those extra days to focus on preparing Haskins to make his first NFL start.

So far, Callahan’s tenure feels a lot like Gruden’s tenure. Washington barely beat Miami, the worst team the NFL has seen in recent memory. On Sunday, it scored no points in dismal conditions. He has a fullback, and he gives the ball to Peterson a lot.

As far as the direction of the franchise, nothing has changed.

“He works us harder during the week,” wide receiver Steven Sims Jr. said. “That’s about it. We just practice a little harder, a little longer.”

More change is needed. Washington is 1-6 with the least-impressive victory conceivable. If this franchise has any chance to reverse its two-decade course, there’s no need to waste time staying focused on the present. If the Redskins don’t change how they approach the rest of the season, it will ensure only one outcome: The slide is only going to continue.