Nationals Manager Dave Martinez comes out to get closer Sean Doolittle after the left-hander gave up three home runs in the ninth inning of Saturday’s loss to the Brewers. (Jonathan Newton/The Washington Post)

The Washington Nationals traded for multiple relief pitchers at the July 31 deadline for two reasons. First, to build a better bridge to excellent closer Sean Doolittle. Second, to add pitchers with experience closing games so Doolittle, who was on pace to pitch more this year than he ever has in his career, would not be ground down and get hurt.

Somehow, Manager Dave Martinez missed the second half of the memo. Now, with Doolittle going on the injured list Sunday, the Nats are paying the price. The IL cause is “right knee tendinitis.” It might as well be listed as “too much Martinez.”

What every Nationals fan knows, he missed: Cut back on Doolittle’s workload before you damage his season and your team’s October chances.

With new arrivals Daniel Hudson (1.08 ERA in 10 games) and Hunter Strickland (1.29 in eight), as well as the useful Wander Suero, Tanner Rainey and Fernando Rodney, the Nats suddenly had short-term bullpen options and maybe a long-term plan, too.

But Martinez ignored this. Three times in nine days, the Nats led by three runs in the ninth inning. Any solid pitcher will have a high save percentage with such a cushion if previously used in that role. Hudson, Strickland and Rodney fit that description. Yet Martinez picked Doolittle all three times.

“When [Doolittle] comes back, he’ll be the closer. But we’ll have to reevaluate situations to make sure. We talked about this today. We have six weeks to go and then some,” Martinez said, referring to the postseason. “We need him for the duration. We need Doolittle to pull this off. And he understands that.” (Jonathan Newton/The Washington Post)

Sometimes the baseball gods decide to make a point. This time, they made the point in triplicate. In those three games, Doolittle got only six outs while allowing 10 runs on 13 hits, including five home runs. The Nats lost two of those three, victories they may dearly wish they had back come September. The Nats lost, 15-14, in 14 innings in the early hours of Sunday morning after Doolittle blew an 11-8 lead by allowing three gruesome ninth-inning homers. Martinez took him out only when the Nats trailed 12-11, as if changing pitchers were against some Closer Code.

Fortunately for the Nats, their hitters took this matter of bullpen mismanagement under advisement, blasting a team record-tying eight home runs in a 16-8 win over Milwaukee on Sunday, a walloping that nobody could hash up.

Before the game, vets spread the word, according to Adam Eaton, that while everybody was exhausted from the previous night, “Who cares? We have to play. So let’s get after it. Jump on ’em quick.” As in, 13-0 after three innings. The Nats have some remarkable collective qualities. Even more reason not to waste them.

“Five out of six [on this homestand], we’ll take it,” said General Manager Mike Rizzo, who has assembled a deep, designed-for-October team that has won nine of 12 to move into pole position for the top NL wild card while remaining just ­5 1/ games behind the National League East-leading Atlanta Braves. All this winning provides sugarcoating to make the Nats’ continued bullpen failures — and Martinez’s handling of the relievers — a bit less bitter. But not much.

In baseball, relying on cliches is the easy way to avoid thinking. If you don’t trust your own judgment or don’t want to own unconventional or unpopular decisions, then the way to hide is to depend on rote rules of thumb.

“Doolittle’s the closer. He’s the closer of this team. We’ve said that before, and this is based on conversations with Doo,” Martinez said after announcing Doolittle’s IL trip. “If he’s available, then he’s going to pitch the ninth inning. He’s always been in the game when he said he was available to pitch.”

So the closer is the closer. (And, by the way, don’t blame the manager.) If the closer says he can pitch, that ends the discussion.

Oh, yeah? Since when? When did that become the 11th commandment?

For 50 years, managers usually have called on their closers when they led by three runs or fewer. That is, except for the thousands of times when the closer was not the closer because the manager decided to be the manager.

Ever since the Nats bolstered their bullpen, Martinez should have been looking for every way to give Doolittle a lighter load instead of using him eight times in 14 games. The reasons are longer than a fungo bat.

Doolittle was on pace to throw 21 percent more pitches than he ever has in his career — 930 so far this season compared with 1,020 in 2013, the only full season in his career when he has stayed off the IL. For context, would you ask a starter with an injury history, such as Stephen Strasburg, to throw 260 innings when the most he had ever thrown was 215? You would just be begging for trouble. That’s what the Nats now have with Doolittle. Will he be his usual effective self when he returns?

Doolittle has also been asked to get more than three outs six times this season, a career high. He has had to throw 20-plus pitches in a game 18 times; last year he did that only six times. He has pitched back-to-back 11 times (a career high) and also pitched in both games of a doubleheader.

The Nats were lucky. Doolittle made it to Aug. 1 intact — staggering a bit but still with a 3.00 ERA. But Martinez kept pushing, even though the balky right knee that has bothered the southpaw for years was barking again.

The Nats probably will come out of this Doolittle episode all right, just as their recent patience with Max Scherzer probably will pay off. The Nats, against Scherzer’s preferences, asked him to throw a second simulated game against teammates Saturday rather than start immediately in the majors. That was smart. Now Scherzer probably will pitch Thursday at Pittsburgh for only the second time since July 6.

In the past two months, Martinez and Rizzo, who’s involved to some degree in everything, have learned that Scherzer’s evaluation of his own body is not foolproof. And neither is Doolittle’s. They’re both bumptious and have been correct many times in saying, “Skip, I’m ready to go.” Now, at 35 and 32, they may need more adult supervision.

Martinez said that, in the future, his conversations with Doolittle will have a different tone. The pitcher may say, “Give me the ball,” and Davey may say, “Not today.”

“When [Doolittle] comes back, he’ll be the closer. But we’ll have to reevaluate situations to make sure. We talked about this today. We have six weeks to go and then some,” Martinez said, meaning the postseason. “We need him for the duration. We need Doolittle to pull this off. And he understands that.”

But does Martinez understand it? In the heat of battle, trying to win every possible game, as he has every day since he got the job, will he be able to take the longer view sometimes?

As the Nats battled from 19-31 to 67-56, they had to ask some key players to carry more than their weight. Doolittle was No. 1 on that list. “We’re competing [for a playoff spot] because Doo has been so good,” Martinez said.

That’s true. But when Doolittle and Scherzer return, the process of decision-making should be somewhat different. Managers need to ask players to evaluate their own health. And players should be honest. But that’s not the end.

The boss must see the whole picture and use a lifetime of baseball judgment to conceptualize beyond “Let’s go 1-0 today,” important though that bromide is.

There’s a name for that difficult job: managing.