Daniel Murphy began a rehab assignment Saturday. (Jonathan Newton/The Washington Post)

MIAMI — A flood of injuries have made navigating the early waters difficult this season, but the Washington Nationals, six games over .500 entering Sunday, are streaking on the field and finally seeing significant progress from injured pieces off it.

The latest positive developments occurred several hundred miles and 18 hours apart. On Saturday, second baseman Daniel Murphy and outfielder Brian Goodwin began rehab assignments playing seven innings each for Class AA Harrisburg. Goodwin, batting second and playing left field, went 1 for 4 and stole a base. He has been on the disabled list since April 17 with a left wrist injury he suffered diving for a ball over a week earlier.

Murphy, batting third and playing second base, also went 1 for 4 and scored a run. Most importantly, Nationals Manager Dave Martinez said, Murphy went first to third on a play without a hitch. Running was the final obstacle in Murphy’s rehabilitation from microfracture knee surgery in October. The dash was encouraging.

“He’s going to hit,” Martinez said. “It’s more of the running portion of it and him having the confidence to go first to third. That’s pretty good. That’s a good indication.”

Murphy and Goodwin were both slated to play for Harrisburg again Sunday. Their next steps, however, were unclear.

“Just continue to keep playing,” Martinez said. “Maybe play back-to-back days. Get them up to nine innings a couple times and we’ll see where they go from there.”

Meanwhile, Ryan Madson threw his first bullpen at Marlins Park on Sunday since landing on the 10-day disabled list with a pectoral strain last Sunday. Madson said he played catch at 90 feet with 100 percent effort Wednesday, Friday and Sunday, and didn’t feel any discomfort. He’ll likely throw a couple bullpens before the Nationals figure out what’s next for him.

“Maybe rehab, but for a guy like him, you might not need a rehab [assignment],” Martinez said. “Maybe just a couple bullpens and see where we’re at.”

Madson was eligible for reinstatement starting Sunday, meaning he could join the Nationals bullpen this week in either Baltimore or Atlanta. His addition will be significant. He’s their eighth-inning setup man, a crucial cog acquired as part of the Nationals’ midseason bullpen overhaul last July. He’s battled a couple nagging issues, one stemming from overuse, and has a 4.19 ERA in 19 1/3 innings, but when he’s fresh and healthy he remains dominant.

When Madson does return, Washington will have a decision to create a spot on the roster for him. Sammy Solis, Trevor Gott, Wander Suero and Tim Collins are the four Nationals relievers with minor league options remaining. Barring an injury that opens a vacancy, one of them will probably get sent to the minors when Madson is ready.

NATIONALS (28-22)
Trea Turner SS
Bryce Harper RF
Anthony Rendon 3B
Matt Adams 1B
Juan Soto LF
Michael A. Taylor CF
Wilmer Difo 2B
Pedro Severino C
Stephen Strasburg P

MARLINS (19-32)
Derek Dietrich LF
J.T. Realmuto C
Starlin Castro 2B
Justin Bour 1B
Brian Anderson RF
Miguel Rojas 3B
JT Riddle SS
Lewis Brinson CF
Elieser Hernandez P

Read more on the Nationals:

Nationals reliever Matt Grace to go on rehab assignment Monday

Max Scherzer struggles, but Nats’ offense picks him up in win over Marlins

Nationals officially call up right-handed reliever Justin Miller