On Voth's velocity, a bullpen opening and Zimmerman's rehab

Some thoughts and observations to help get you through the Nationals' first day off in nearly two weeks before they return to action Tuesday night in Miami ...

* The most significant development of Sunday's 10-inning loss to the Braves didn't occur in the late innings. It might well have happened in the first six, when Austin Voth authored by far the best outing of his brief major league career.

Pressed into emergency starting duties to compensate for the pair of rainouts at the start of the week, Voth entered this game with minimal expectations. But with each passing inning, the rookie right-hander (who turns 27 on Wednesday) did more to raise the bar and give the Nationals new reason to look at him in a different light.

Having bulked up over the winter and worked out at the increasingly popular Cressey Sports Performance facility in Florida, Voth added several miles per hour to his fastball. He consistently threw it 95-96 mph Sunday, and he threw it in the strike zone. He wound up with a career-high seven strikeouts, and though he surrendered two solo homers, that's not the reason the Nats lost the game.

"He's got a lot of life on his fastball," said Yan Gomes, who caught Voth for the first time. "We saw that throughout the game. He was able to locate some really good heaters. The big thing when you get somebody newer or younger coming in is nitpicking the zone. And he wasn't. He was just being really aggressive and letting them take swings off him."

Voth figured to be a short-term fill-in to get the Nationals through the weekend. Their rotation should be set for the remainder of the first half, with Max Scherzer, Patrick Corbin and Stephen Strasburg set to start the next three nights in Miami and Erick Fedde and Aníbal Sánchez to follow in Detroit before Scherzer retakes the mound Sunday in his old stomping grounds.

Then again, perhaps Voth earned the right to get another look up here. Fedde hasn't been real sharp in his last two starts, walking eight and allowing seven runs in 9 2/3 innings.

"We'll see where he fits in, but I was very impressed," manager Davey Martinez said. "Especially in the sixth inning, still throwing 94 mph. And looked very poised. It was awesome."

* Whether Voth stays or goes, the Nationals should have at least one more pitching move before they open their series with the Marlins. Kyle McGowin was promoted from Triple-A Fresno to provide some bullpen depth Sunday, but he wasn't needed thanks to Voth. And with the big three starting the next three nights, there doesn't seem to be need for a traditional long reliever.

So the door is open for the Nats to summon a more traditional reliever. And with Trevor Rosenthal gone, there's an opening on the 40-man roster if they want to pick someone we haven't seen yet this season.

Though there are a couple of veterans with significant major league experience (Fernando Rodney, George Kontos) currently pitching in relief for Fresno, neither has impressed to date. The guy who has impressed the most is right-hander Dakota Bacus, who in 28 appearances has a 1.14 ERA and 1.12 WHIP.

Acquired from the Athletics way back in 2013 for a catcher named Kurt Suzuki, Bacus is a 28-year-old with zero big league experience. But he could get his long-awaited shot soon.

* Ryan Zimmerman played in rehab games for Double-A Harrisburg on Friday and Saturday, and he'll be back in action there tonight.

Zimmerman, out since April 28 with plantar fasciitis in his right foot, is scheduled to play seven innings at first base again as he works his way back into shape. Martinez had previously said he wanted the veteran to play a full nine innings before activating him off the injured list, so that would seem to suggest Zimmerman will be sticking around Harrisburg for another day or two.

That also means Zimmerman's return from the injured list would more likely come at the end of the week in Detroit (where the Nationals will need a DH) than in time to play in Miami to begin the week.