Sean Doolittle and Roenis Elías each threw an inning in a simulated game this afternoon, potentially the final step for each reliever before returning to the Nationals' active roster this weekend.

Doolittle, on the 10-day injured list since Aug. 18 with right knee tendinitis, and Elias, on the 10-day IL since Aug. 4 with a right hamstring strain, each faced live hitters today for the first time and each was encouraged by the results.

"I'd like to have them both back as soon as possible," manager Davey Martinez said. "That would be nice. But at the same time, we have to make sure we check all the boxes."

Doolittle threw 16 pitches to teammates Gerardo Parra and Spencer Kieboom, who noted his slider and changeup were sharper than usual. The left-hander, who used the break not only to let his knee heal but also to give his arm and head a much-needed rest, had his session filmed so he and members of the Nationals coaching and training staff can view his mechanics and evaluate how he looks.

If he recovers well from today's session, Doolittle could return to the active roster this weekend, though Martinez sounded a bit more cautious about him than Elías.

"It all depends on how he feels tomorrow," the manager said. "I know he was going to condition, do some weight stuff after he threw, and then we'll see how he rebounds tomorrow. I'm curious to see how he feels tomorrow."

Elías appears to be on track to be activated Friday, barring any complications between now and then. The lefty, who hurt his hamstring running out an infield chopper in his Nationals debut Aug. 2 in Arizona, also faced Parra and Kieboom, who were impressed with his curveball and changeup in addition to his mid-90s fastball.

"It's definitely an important step forward," Elías said via interpreter Octavio Martinez. "I felt great, and I think I'm closer to coming back and helping the team any way I can."

Elías did note his mechanics were a little off, but he said that was to be expected after missing four weeks. The Nationals seem to believe he's all but ready to return.

"He definitely has checked all the boxes," Martinez said. "He's raring to go. ... If he comes back tomorrow and says there's no issues with his hamstring, he doesn't feel anything, then he should be back for the weekend."

Elías was asked what his approach will be if asked to bat again. He smiled and offered up a sensible answer.

"That's prohibited for me anymore," he said with a laugh. "If they want to throw three straight fastballs down the middle, go ahead. I'll just take all of them."