(Evan Vucci / AP)

Just over 24 hours before Thursday’s 4 p.m. non-waiver trade deadline, a contingent of Nationals decision-makers are in Miami. General Manager Mike Rizzo is usually with the team, but principal wwner Mark Lerner is also here, along with some of Rizzo’s staff.

And each day — even twice a day, in recent days — Rizzo and Manager Matt Williams have talked about trade options. The Nationals don’t need to make a trade given the lack of glaring holes on their big league roster and Rizzo has said he won’t place the urgency of this season ahead of the organization’s long-term outlook. But the Nationals are still working in preparation for a possible deal.

They have been scouring for a reliever to deepen their bullpen. They’ve been looking for young shortstops and their work on that now could be more laying groundwork for the winter. And with the Nationals’ silence about Ryan Zimmerman’s timetable for recovery sending a big signal that he will be out for a while, they could also be in the market for an infielder.

“There’s nothing that we’ve decided on yet,” Williams said of his conversations with Rizzo. “Things could change drastically over the next 24 hours. I’ve been talking to him every day and he’s been extremely busy and speaking with a number of people around the league about potentials. We’ll see what happens. It’s always comes down to the 11th hour anyway. All of those frying pans are going right now and we’ll see what we can come up with anything.”

Asked how the extent of Zimmerman’s injury would affect the Nationals’ trade deadline plans, Williams again said they didn’t know yet. The Nationals have declined for a week since Zimmerman’s injury to reveal the grade of hamstring strain and how long they expect him to be out.

The Post reported on Monday that Zimmerman may be out a while, perhaps the majority of the rest of the season with a substantial hamstring strain. MLB.com reported late Tuesday night that Zimmerman suffered a Grade 3 strain, the most severe hamstring strain.

The Nationals seem to be withholding a precise timeline so as not to harm their leverage in trade talks. But their silence and admission that Zimmerman’s injury was substantial is perhaps just as telling. Twenty-hour hours before the deadline is still a lot of time.

“We just gotta wait and see what happens,” Williams said. “There are some guys that are out there, there are some guys we’ve taken a hard look at. We’ll see how it goes. Right now, we don’t have anything concrete.”

Rizzo and Williams have both expressed confidence in Danny Espinosa at second base — along with a mix involving Zach Walters and Kevin Frandsen — in Zimmerman’s absence. Espinosa provides exceptional defense but is hitting .212/.280/.344 with 101 strikeouts entering Wednesday. The Nationals are 38-33 in games Espinosa has started and 19-14 when he doesn’t. The Nationals are in first place by half a game entering Wednesday thanks, in part, to Espinosa, who played every day for much of the season, Williams said.

“We are where we’re at and we’ve got a chance,” Williams said. “He’s helped us have that chance. Whether it’s Danny, Franny or Zach, or a combination of all three. Whatever it is. Whether it’s Franny at third sometimes and moving Anthony back over there or Zach over there. That’s part of the process you have to go through. If nothing happens, that’s the way we’ve played the majority of the season anyway. So everybody would be comfortable with it. We still have to do things right and wins games.”