Sean Doolittle was gassed, clenching his fists and letting loose a scream, then crouching on the mound after striking out Yadiel Rivera to finish off the Miami Marlins on Wednesday night.

It was, by any measure, a hectic save for the Washington Nationals’ closer. Doolittle loaded the bases. He gave up a run by hitting a batter. He got up to 33 pitches, a season high, and finally beat Rivera with a high fastball to sidestep disaster. Doolittle later admitted his heavy workload might have caused fatigue, and the July humidity didn’t help. But the larger point is that the Nationals cannot rely on just one reliever in big situations, as they have all year, or Doolittle will get burned out.

So about 16 hours later, in the series finale with the Marlins on Thursday afternoon, with Washington holding a three-run lead, 42-year-old Fernando Rodney rode the bullpen cart into a save opportunity. Doolittle was unavailable. Manager Dave Martinez had mapped out his relievers that morning, beginning with Tanner Rainey, then Wander Suero, then Jonny Venters and Javy Guerrawhen Suero wilted, then Rodney for the ninth. Auditions to be the Nationals’ setup man/secondary closer have been simple this season: Pitch a scoreless inning, and you get another chance, and another, and another until either your arm tires or you prove fit for the job. Trevor Rosenthal had failed and was released. Kyle Barraclough struggled, too, before landing on the injured list. Suero is in the midst of fumbling away his opportunity.

And Rodney, baseball’s oldest pitcher, might just be getting started.

“If he can do that and Doo can’t go, he’s going to be the guy,” Martinez said of Rodney on Thursday, and no one could have expected to hear that July 4.

What Rodney did, really, was enter a game with a lead and exit it without starting a fire. That may seem like a low bar — and it is — but it also makes him one of Washington’s relievers of the moment. Martinez has searched all year for anyone who can get outs with consistency, strand inherited runners and minimize the need for Doolittle every night. That pitcher has emerged only in flashes before waning, leaving the manager with a new puzzle to solve. Now the additions of Rodney and the 34-year-old Venters, however odd or uninspiring, seem to be pointing the bullpen in a better direction.