Samaje Perine missed practice Saturday, adding to the Redskins’ injury woes at running back. (John McDonnell/The Washington Post)

Because most NFL teams rarely use their starters in the fourth preseason game, Washington Redskins Coach Jay Gruden plans to use the days before Friday’s third game — against the Denver Broncos — to replicate regular season action as much as possible. The Redskins will practice and install a game plan exactly the way they would before the opener at the Arizona Cardinals on Sept. 9.

If only he can find enough healthy wide receivers and running backs to imitate his final roster.

Washington practiced with only three running backs Saturday, the result of more injuries at a position that can’t handle much more calamity. Derrius Guice, who was expected to play the role of the team’s top backfield threat, is out for the year, and now the Redskins’ two third-team backs are out after getting hurt in Thursday’s victory over the New York Jets.

Samaje Perine, who sprained his ankle after breaking off a 30-yard run against New York, missed Saturday’s practice, as did Byron Marshall, who left the game late with a lower leg injury. Gruden did not give an update on either player’s condition or even suggest they can be ready for Week 1. He offered little beyond: “They should be okay.”

Also on Saturday, the team waived a third running back who was injured in the game, undrafted free agent Martez Carter.

With only Chris Thompson, Rob Kelley and Kapri Bibbs left as healthy running backs, Gruden said the team is bringing in a handful of players for workouts with the possibility of signing at least one this weekend.

“I’m going to get the list as soon as I go in to see who is coming in for this workout,” he said. “It will be fun to see. We’ll see.”

After Guice went down, Redskins officials said they weren’t looking to sign another running back, even though players like Adrian Peterson, Eddie Lacy, Jamaal Charles and Orleans Darkwa remain unsigned.

The injuries are not limited to running back, however. Several wide receivers also missed Saturday’s practice, including starter Jamison Crowder, backup Brian Quick and undrafted free agent Cam Sims, who made several key catches in the Jets game. Gruden said he hoped all would return “soon” but did not provide a timetable.

Washington added another player to an already competitive battle for the final roster spot at wide receiver, signing Allenzae Staggers, who went undrafted out of Southern Mississippi in April’s draft. Staggers, who played wide receiver and returned kicks at Southern Miss, is 6-foot-3, giving the Redskins another tall pass catcher. Washington has struggled in the red zone in recent years, making big targets who can leap to grab passes in the corner of the end zone a priority.

“We had a couple workouts and we liked his frame,” Gruden said, conceding that Staggers “has a lot to learn in a short period of time.”

As if it weren’t enough to have just three running backs and a smaller-than-usual number of wide receivers Saturday, the Redskins also practiced without tight end Jordan Reed, who missed the workouts with a virus.

In addition to Staggers, the Redskins also signed tackle Kendall Calhoun and defensive back Darius Hillary. Calhoun, who is 6-foot-7 and is reported to have a 7-foot-2 wingspan, signed with the Houston Texans in the spring but was cut before camp.

The Redskins also waived linebacker Jeff Knox and defensive end Jalen Wilkerson.

Read more on the Redskins:

Roll, Tide: Ex-Alabama teammates Daron Payne, Jonathan Allen show out for Redskins

Redskins-Jets takeaways: Daron Payne, Jonathan Allen look like difference-makers

The Redskins-Jets game wasn’t worth paying for. But at least Alex Smith didn’t get hurt.