Last year the Washington Nationals showed they could say no — to Bryce Harper. Now they need to show they can say yes — to Anthony Rendon.

On Friday, Rendon turned an imminent loss into a win with a two-run, walk-off hit. In a brief on-field interview, he implored the fans to support the team as the Nats try to catch the Atlanta Braves for their fifth National League East title in eight years.

“Tell your friends; tell your family. We need you!” he said.

That is nothing compared with how much the Nats — and the Lerners — need Rendon, who is in the last month of his walk year. Just hope they know it.

As if to underline this point, Rendon homered twice Saturday as the crowd chanted, “MVP! MVP!” for the man who now leads the NL in batting (.337), is second in RBI (111) and is third in on-base-plus-slugging percentage (1.056) — all-around wonderful.

In his past 21 games — including a walk, a single and a two-run homer in the Nats’ 9-3 win over Miami on Sunday, Rendon is hitting .437 with eight homers, 24 RBI, 22 runs and a 1.361 OPS. Babe Ruth’s career OPS was 1.164, the bum.

For decades, players were said to make “a salary push.” Rendon appears to be making a continent push — his choice. If he only wants Europe, give it to him.

After his second homer Saturday, Rendon was stumped on a new move in the Nats’ dugout dance celebration. “We booed him,” Brian Dozier said.

“Oh, they booed me bad,” said Rendon, who had consulted with catcher Kurt Suzuki’s son, Kai, age 5, about possible dance moves if he should homer. Kai suggested the Macarena. Rendon figured he was all set. Then dad — Kurt Suzuki — homered and, you guessed it, did the Macarena.

When Rendon homered a few innings later, he realized the Macarena was old news. “I blanked,” he said. “I surrendered.”

On Sunday, Rendon made sure to atone. When his blast disappeared to put the Nats ahead to stay, he obliged his mates with a shimmy and a shake.

Now, for the big question: Will the Lerners oblige Tony with $225 million?

With the Nats about to face 16 straight games against contenders, including seven with the Braves, this is probably not the time to get a megadeal done. But it is the time for the Lerners to get their heads around what has happened to their wallets after the All-Star Game. Rendon has hit .389 since then. He hasn’t changed the game. He already has won it.

Up till now, the Nats have signed their homegrown stars if they take hometown discounts (Stephen Strasburg, Ryan Zimmerman) but let them walk when they won’t (Ian Desmond, Jordan Zimmermann).

With hindsight, it appears that was the Nats’ strategy with Harper. The Nats could see a future with Harper as slugger and drawing card. But they could also see a future, as good or better, without him — provided they spent all that money wisely.

Meanwhile, the Nats have made fat bids, with a year or more of extra pay that nobody else offered, to free agents who — key factor — fit a huge need. That’s how they won Jayson Werth, Max Scherzer and Patrick Corbin, all those signings bewailed as awful overpays at the time. They also offered Mark Teixeira more than $180 million and Prince Fielder a similar fortune.

Now times must change. Rendon is not a homegrown star who can be replaced by a farm-system product, the way Juan Soto, Trea Turner and Victor Robles repopulated the lineup.

Rendon is irreplaceable right now. He’s the player who, if the Nats didn’t already have him, they would have to go out and get because he’s just what they need to pair with the fabulous Soto in the heart of their order for years.

The comparable is Colorado third baseman Nolan Arenado, a 28-year-old who signed an eight-year, $260 million deal in February. Rendon will be 30 next year. The cost of the Arenado deal for his age-30 through age-35 seasons is $199 million.

If the Nats need to overpay Rendon to keep him — and I think they do because their attendance has dropped from 11th in the majors to 16th this year, and they can’t afford to subtract another drawing card — then we’re in the ballpark of $225 million or more.

The Lerners need to get there — and not with tons of deferred money — before Rendon hits the open market in November. Once the whole world is bidding, players tend to end up elsewhere.

That better not happen to these Nats. Their lineup is fearsomely synchronized with Rendon and Soto perhaps the best right/left-hitting No. 3-4 tandem in the game. In this case, 1 plus 1 is more than 2. Subtract Rendon, and in 2020 at age 21, Soto is isolated. That can’t happen.

Rendon knows every bit of this puzzle. He likes Washington plenty. But, now fewer than 30 games from being free, he’s not going to be a hometown-discount guy — and he shouldn’t be.

His bat and glittering glovework at third base — as well as his laid-back, funny, friendly personality in the clubhouse — make him an ideal franchise player. His very nature is daily oil for the Nats’ smooth-running gears — just as Harper, by nature, sometimes unintentionally put sand in those gears.

Right now, the Nats have a wonderfully entertaining future — if Rendon remains at the center of it. With him, the Nats, on a 92-win pace, can use the offseason to fix their horrid bullpen and expect to win 95 or more in 2020. With their top six starting pitchers under team control, as well as all of their major lineup pieces, it should be light lifting for General Manager Mike Rizzo to get the Nats beside the Dodgers and Braves as the class of the NL. Probably in 2021, too.

Without Rendon — shudder — a lot of work and worry are ahead this winter. What team wants to face that risk in back-to-back seasons?

In the Nats’ 58-27 surge, the whole team has been awash in delight, plus a bit of amazement — are we this good? Is this the best Nats team so far? Are we sneaking up on an October run?

Rendon’s contract is not on any of the Nationals’ lips, but it should be on the Lerners’ minds. On Sunday, all Rendon wanted to talk about was the noise that he hoped to hear at raucous Nationals Park this month and in October.

“When we are on the road and we hear 30,000 people yelling, we say, ‘This is what it’s like when they are against you,’ ” he said. “It’s a huge boost when you have it with you. We want [our fans] to put that pressure on the other team.”

No one knows whether this is Rendon’s last season in Washington. But one factor would work in D.C.’s favor: winning.

“Anthony is humble. But in this game, sometimes you don’t get as much recognition if you’re not showy,” Dozier said. “So a humble guy can also have a chip on his shoulder, and I think Anthony does.”

What can the Nats do to help keep Rendon — his sly grin, his quick bat and his invisible chip — in D.C.?

“Everybody in here is thinking about just one thing: Let’s make a World Series run,” Dozier said, grinning. “That usually makes everything work out better.”