Solis hits "roadblock," but new lefties stepping up in Nats bullpen

It has been one of the bigger questions facing the Nationals all season: Which left-handed reliever (or relievers) can they trust when crunch-time arrives?

The answer to that question has changed several times in five months. Felipe Rivero and Oliver Perez were the primary left-handers in the Nationals bullpen back in April, but then Sammy Solis emerged as manager Dusty Baker's top southpaw as May turned to June and July.

Then Rivero was traded to the Pirates in the Mark Melancon deal and Solis wound up on the disabled list with shoulder inflammation. Enter Marc Rzepczynski, acquired in an August waiver trade with the Athletics. And enter Sean Burnett, acquired in August in a minor league deal and then added to the big league roster for September.

So where does all that leave the Nationals as they reach the stretch run and start pondering postseason possibilities?

It's still an open-ended question, in part because of Solis' attempt to return from injury. That attempt has "hit sort of a roadblock," Baker revealed today. Solis still has visions of returning before season's end, but he remains an uncertain entity for now.

"I'm very hopeful," Baker said. "We could use him, big time. 'Cause Sammy, he was lights-out. He was very good. He gave us a different option from our specialty lefties. He could give us an inning and a fraction, two innings, equal with right-handers up there."

The good news, from the Nationals' standpoint, is that both Rzepczynski and Burnett have performed well since joining the club.

Rzepczynski hasn't given up an earned run in six appearances, surrendering a hit in only one of those. And he has been more than a specialist so far, facing at least three batters in each of his last five appearances, proving to Baker and pitching coach Mike Maddux he can be trusted to get right-handed batters out.

"Rzepczynski was good before we got him," Baker said. "His arsenal is ground balls. But I didn't know him. I'm just looking at the stat sheet. I might leave him (in) now against some righties because he seemed shocked when I was taking him out the first time. But we were going right-left-right-left because we had the bodies. And so, he looked at me like: 'What are you doing out here? I can get righties out, too.' But if you don't know a guy, or haven't seen a guy in years, then you have a tendency to kind of protect him."

Burnett, meanwhile, has been used in short, quick doses, facing a total of six batters in four appearances. He surrendered a double to the only right-handed batter in that group, but has retired all five left-handed batters who have faced him so far.

The 33-year-old hasn't pitched consistently in the majors since he was last with the Nationals in 2012, so this remains a feeling-out process for the club. But Baker likes what he has seen so far.

"Burnie's done a very good job," the manager said. "We haven't seen Burnie yet against righties too much, but he's been good before. And I asked (catcher Wilson) Ramos. I said, 'Give me your assessment' when he went out there the first time. 'Is he the same guy?' And he just said, 'His velocity's down a little bit, but he's the same guy.' "