Justin Miller is now on the 10-day injured list for the second time this season. (Nick Wass)

Justin Miller is back on the 10-day injured list with a strained right rotator cuff. Tanner Rainey was called up from Class AAA Fresno to fill his spot in the bullpen. It is beginning to feel like the Washington Nationals are not allowed to play a game without making at least one roster move before first pitch.

Miller left Friday’s 14-6 loss to the Chicago Cubs with pain in his right shoulder as the Nationals’ bullpen allowed nine runs across the last three innings. Two of those were charged to him. Manager Dave Martinez knew after the game that Miller would go to the IL, saying as much to reporters, and yet Martinez was still unsure, as of Saturday afternoon, whether Rainey would make it in time for the 7:15 start.

“Oh, Tanner Rainey made it,” Martinez said when alerted during his pregame news conference that the move was complete. It has been like this all season, one full of injuries and shuffling and reshuffling and odd-hour flights from Fresno to wherever the Nationals are. Rainey, a right-handed reliever, joins the team with Miller making his second trip to the IL.

Miller had pitched well after returning from a lower-back strain but slipped in his past two appearances before landing back on the shelf. There he joins first baseman Ryan Zimmerman (plantar fasciitis in his right foot), first baseman Matt Adams (left shoulder strain), starter Aníbal Sánchez (hamstring strain), reliever Tony Sipp (oblique strain), reliever Trevor Rosenthal (viral infection, and an inability to command his pitches), reliever Austen Williams (sprained right AC joint in his shoulder), outfielder Andrew Stevenson (back spasms) and reliever Koda Glover, who is on the 60-day IL with a right forearm strain.

The Nationals recently brought Trea Turner, Anthony Rendon and Juan Soto off the IL. But they remain banged-up. They are without three of their Opening Day relievers. Victor Robles was hit in the wrist with a pitch Friday and is out of the lineup as a precaution (though he is available to pinch hit). Michael A. Taylor starts in Robles’s place for Washington’s matchup with the Cubs. And Martinez announced before the game that Erick Fedde, transitioned to the bullpen in late April, will start in Sánchez’s place against the New York Mets at Citi Field on Tuesday.

It is a lot to keep track of and a lot to coordinate with players such as Rainey traveling cross-country at a moment’s notice. Rainey, 26, came from the Cincinnati Reds in December in a trade for starter Tanner Roark. He debuted for the Reds last season and in eight appearances had a 24.43 ERA and struggled to command a high-90s fastball. He soon will get another shot in the majors, maybe even Saturday night, and the Nationals are still looking for a reliever not named Sean Doolittle to find a stride.

Rainey had a 4.00 ERA, 32 strikeouts and 12 walks in 18 innings for Fresno. The Nationals need the swing-and-miss stuff to translate and the command to improve. And they need that to be a realistic ask for as long as Rainey is with the team.

“He’s got a live fastball and his slider, toward the end of spring training, was really, really good,” Martinez said Saturday. “He continued to progress in Triple A this year, and he’s been pitching well.”

LINEUPS

Cubs (26-16)

Kyle Schwarber, LF

Kris Bryant, RF

Anthony Rizzo, 1B

Javier Baez, SS

Wilson Contreras, C

Jason Heyward, CF

Addison Russell, 2B

David Bote, 3B

Jon Lester, P

Nationals (18-26)

Trea Turner, SS

Adam Eaton, RF

Anthony Rendon, 3B

Howie Kendrick, 1B

Juan Soto, LF

Brian Dozier, 2B

Yan Gomes, C

Michael A. Taylor, CF

Stephen Strasburg, P

Read more on the Washington Nationals:

Nationals’ bullpen implodes again, turning series opener against Cubs into a laugher

Boswell: Those offseason fixes Nats made to the back of their rotation? They got it wrong.

Gerardo Parra plays hero again, helps Nationals take series from Mets