PHILADELPHIA -- The Nationals made a series of roster moves and underwent a significant shuffle within their coaching staff prior to Thursday's seven-inning doubleheader against the Phillies at Citizens Bank Park.

In addition to the 12 reported positives on Wednesday afternoon (four players, eight staff members), one other staff member's test came back positive on Wednesday evening, bringing the total to 13. All of the follow-up tests on other players and staffers have come back negative.

The Nationals placed shortstop Trea Turner, catcher Alex Avila and right-handers Daniel Hudson and Austin Voth on the injured list without any designation. Avila had already been on the 10-day IL with bilateral calf strains, though he had been participating in baseball activities and eyeing an August return.

To fill those spots, the club recalled infielder Luis García and right-hander Andres Machado. The Nats also reinstated Yan Gomes and Tanner Rainey from the 10-day injured list. In a separate move, the team optioned catcher Tres Barrera to Triple-A Rochester.

"I talked to everybody, everybody seems to be OK health-wise," manager Dave Martinez said. "That's great. Like always, we're gonna get through this together and hopefully everybody comes back soon."

Washington will also a deploy a makeshift coaching staff for the twin bill. Coaches who are not with the team include Randy Knorr (first base), Bob Henley (third base), Jim Hickey (pitching), Tim Bogar (bench) and Pat Roessler (assistant hitting).

"They're all frustrated, they don't like missing any games," Martinez said. "Bogey did some work this morning for me which he typically does. But I told them, 'We'll get through this and just make sure you guys stay healthy, that's the biggest thing, and stay safe.'"

As replacements, the Nationals will turn to Gary Thurman (first base), Henry Blanco (third base), Sam Narron (pitching) and Brian Daubach (assistant hitting).

And bench coach?

"Bench coach will be me," Martinez said. "I'll tell you, Kyle Schwarber will help me bench coach by the way.

"We'll do fine. I talked to all these guys this morning, they're excited. We'll get through it. These guys come in ... they're excited to be here."

The Nationals reached the 85% vaccination threshold for lowered COVID-19 restrictions in late May. All but one of the 13 individuals to test positive were vaccinated, according to Martinez. He added that some are experiencing mild symptoms, while the rest are asymptomatic.

"I want to reiterate, and I truly believe from what I've seen, thank God most of us are vaccinated," Martinez said. "It does help. The vaccination does help. I couldn't even imagine going through this with people who aren't vaccinated. There were mild symptoms and that's all it was. I'm really glad that we were vaccinated."

Along with the roster moves and coaching staff additions, the club also brought in some people to help with strength training and the medical team. The Nationals, who begin a three-game series against the Cubs at Nationals Park on Friday, will take the situation day by day and continue to monitor the status of each player and staff member moving forward.

"We'll make due. We'll be fine," Martinez said. "Biggest thing is I'm really close to these guys. It'll be tough to be out there without them, but we'll get through it."