WASHINGTON -- The Nationals are taking steps toward getting their roster back to full strength, after a pair of roster moves to shake up their bullpen prior to Friday night’s 7-6 win over the Marlins on Anthony Rendon’s ninth-inning hit at Nationals Park.

Roenis Elias was activated from the injured list and Hunter Strickland from the paternity list while left-hander Matt Grace was designated for assignment to create space on the roster. Catcher Spencer Kieboom was also optioned, to Double-A Harrisburg.

Both Strickland and Elias entered the game in the seventh inning. Strickland was charged with two runs, giving up three hits and issuing one walk, with one strikeout. Elias followed, issuing a walk with the bases loaded, but then he got Lewis Brinson to ground into an inning-ending double play.

Elias, who was acquired at the July 31 Trade Deadline, returned to the Nats for the first time since he injured his right hamstring in his lone appearance with the team on Aug. 2. Washington acquired him from the Mariners with the hopes that Elias would be able to match up against lefties, a role they have been seeking to fill in their bullpen since the start of the season.

“Elias is ready,” Nationals manager Dave Martinez said before Friday night’s game. “He threw the ball really well the other day. I talked to him, he felt ready. He wants to pitch.”

The need to trade for Elias was created after a pair of southpaws failed in the bullpen earlier this year, starting with Tony Sipp, who was signed in Spring Training and designated for assignment at the start of the month, and Grace, who took on a variety of different roles for the team in the past two seasons.

In 2018, Grace was a surprise unheralded find for the Nationals bullpen, compiling a 2.87 ERA in 56 games and emerging as their top left-hander behind Sean Doolittle. He was not able to replicate that success this season, especially considering his heavy workload out of the bullpen to start the year, which may have contributed to his inflated ERA. Grace pitched in 51 games this year in a variety of roles -- long reliever, LOOGY (left-handed one-out guy), one-inning reliever regardless of matchups -- posting a 6.36 ERA.

“It’s unfortunate,” Martinez said. “I talked to Matt; for two years, whatever his numbers are -- Matt had many different roles, took the ball, never complained, went out there and tried to pitch to the best of his ability to help us win.”

The Nationals now have an open spot on the 40-man roster after Grace was DFA’ed, which could be used to add a reliever when rosters expand Sunday. Greg Holland seems a likely choice.

Doolittle to make Minor League rehab appearance Friday

Doolittle made a Minor League rehab appearance for Class A Advanced Potomac on Friday night, throwing a 1-2-3 fifth inning. This follows a simulated game earlier this week, which Doolittle called “ a mixed bag.”

“Physically, I felt good, my knee and my arm felt really good,” Doolittle assured of the simulated game. “But as far as execution, mechanically, it wasn’t where I wanted it to be in order to help this team in a playoff run.”

Doolittle threw his simulated game under the watch of an edgertronic camera -- a high-speed camera that breaks down his mechanics frame by frame -- the first time he has used such equipment, and he planned to bring a member of the Nats’ video department along to his rehab assignment to use it again.

During his simulated game, Doolittle felt like his pitches were inconsistent and wanted at least one more outing to try and find a better feel for his pitches before coming off the IL. If all goes well, he could rejoin the team Sunday when rosters expand.

Zimmerman to workout with team this weekend

Ryan Zimmerman was back with the team at Nationals Park this weekend, but the Nationals are going to wait until rosters expand Sunday to activate him from the IL. Zimmerman, who has been limited to just 33 games this season while battling separate flare-ups with plantar fasciitis, has not played since July 22 and is expected to work out with the team for the next two days before being activated.

• Inbox: How will Zimmerman fit back in?

“Get him back, get him here, get him to take ground balls, get eyes on him,” Martinez said. “He feels good, looks good. I want him to continue to run the bases the next few days and then hopefully Sunday we will activate him.”

Worth noting

• Adam Eaton was out of the Washington lineup Friday after getting hit by a pitch near his right knee during Wednesday’s game against the Orioles. Eaton was forced to leave that game early, but did try and lobby his way into the Friday night lineup before Martinez shut him down.

• The Nats shuffled their rotation a bit this weekend to give Max Scherzer an extra day of rest, which they believe will help strengthen his back. Joe Ross will start Monday and Scherzer will take the ball Tuesday against the Mets.