WASHINGTON -- The Marlins flew into D.C. on Friday with a pair of injured veterans whom they plan to activate from the injured list on or shortly after they can easily do so as September roster expansion begins on Sunday. By waiting a few days, Miami will have the luxury of not needing to alter its 25-man roster.

But before the final decisions on their returns are made, Marlins manager Don Mattingly wanted to give José Ureña and Miguel Rojas Friday and Saturday to work out and make sure nothing unusual pops up before their likely activations.

“They are both kind of back to full activity,” Mattingly said of Rojas and Ureña on Friday before Miami's 7-6 loss to Washington at Nationals Park. “[We’ll] give them a couple days to make sure they’re still good. The date is coming up that we’ll be able to activate them.”

And when his lanky frame walked into the clubhouse on Saturday, Tayron Guerrero added himself to that list. He has been sidelined since Aug. 9 with a torn fingernail.

“Obviously tomorrow, the rosters expand, we feel like he’s ready to go,” Mattingly said of Guerrero on Saturday. “Soon. I don’t know about tomorrow.”

True to Mattingly’s words, both Urena (herniated disc in lower back) and Rojas (right hamstring strain) took part in pregame workouts on Friday. While Urena threw in the outfield, Rojas took grounders at short and ran in the outfield.

Rojas, who has been out since Aug. 6, should not need to shake off much rust when he returns, given his shorter time on the sidelines and with five rehab games already under his belt.

For Urena, who hasn't appeared in a Major League game since June 7, there will not just be rust to shake off but also an adjustment to a new role. Miami plans to use Urena out of the bullpen when he returns, most likely as the team's closer. Mattingly believes the role should both suit Urena’s aggressive pitching personality and help ease him into the offseason without too much strain on his body, which has already been through its fair share this year.

“I think that’s pretty much it -- to get him back on the mound, to get him competing,” Mattingly said of the hopes for Urena. “Just get him back at the Major League level and send him into the winter with a full bill of health from that standpoint. And then he can go to work like everybody else does in the winter with his [offseason] programs.”

It will not be the first time Urena has come out of the bullpen. He made 33 relief appearances over the course of 2015-17, his first three seasons in the Majors. His first career save came in '16, and he had four more in the Minors.

“I’m pretty excited. The recovery is going well, so we’ll keep the same plan to try and get better every day," Urena said. "For me, I think we will be looking for good health and good recovery because it’s something you can’t play around [with].”

Now with a fastball that averages just north of 95 mph waiting to be used in full force all year, the Marlins will be excited to watch how Urena acts when he knows he’ll consolidate his stuff in just one or two innings. In five rehab appearances in the Minors, the righty posted a 1.69 ERA while walking one and striking out three.

“To see how he reacts out of that will be interesting, too, because we feel the role we plan on using him in kind of fits his personality and his mentality,” Mattingly said. “That should be interesting to see.”

Yamamoto expected back this season

At some point before the 2019 season comes to a close, the Marlins expect Jordan Yamamoto to return to the mound in a Major League game. It's positive news for the 23-year-old right-hander, who started his rookie season lights out before hitting some bumps as of late.

Until he does return, Yamamoto has been limited to only playing catch due to Hurricane Dorian bound for South Florida. He has been rehabbing from a right forearm strain that landed him on the shelf on Wednesday.

“That’s what we’d like,” Mattingly said, “to make sure he goes into the winter with the mindset of: 'I’m healthy; I’ve pitched. Now I just need to get my winter workouts and be ready for next year.'”

Riddle hits setback

Just when it seemed that JT Riddle was nearing the end of his month-plus-long recovery from a right forearm strain, the infielder hit a snag.

The Marlins returned Riddle from his rehab stint on Friday and sent him back to Miami for further evaluation after he experienced soreness in his right forearm. He’ll be evaluated by trainers, and the team will most likely determine his next steps and availability for the remainder of the season after that.