When asked about his starting rotation Sunday, and whether a semi-encouraging outing from Paolo Espino helped him see a short-term fix, Dave Martinez made an admission that, while obvious, was important for the discussion at hand: “I can’t predict what the future is going to be.”

That’s one certainty of the Washington Nationals’ immediate pitching plans. The other is ... well, no, that’s it.

Stephen Strasburg is on the 10-day injured list with right shoulder inflammation. Martinez, the Nationals’ manager, said there is no timetable for his return. Jon Lester remains on the coronavirus-related IL while building his pitch count at the team’s alternate site in Fredericksburg. Martinez used Espino, a 34-year-old with little major league experience, to fill in for Strasburg against the Arizona Diamondbacks on Sunday. (The game ended in a 5-2 loss, though that wasn’t Espino’s fault.) Otherwise, the staff is filled out by Max Scherzer, a struggling Patrick Corbin, Joe Ross and Erick Fedde.

Which funnels right into the pressing question: What’s next?

Espino was a quick fix for a scrambling club. Now, though, the Nationals could lean on a handful of days off — and Lester’s pending return — to avoid any major changes to their roster. Austin Voth, for example, could stay in the bullpen if the Nationals ride a four-man rotation until Lester is ready. And Espino could be sent back to Fredericksburg, making room for another reliever.

A starter typically needs four days of rest between appearances. Because Lester is still at the alternate site, what follows is a mock-up rotation schedule that doesn’t include him. Notice that the four healthy starters — Scherzer, Corbin, Ross and Fedde — would be on at least four days’ rest through a May 7 matchup with the Yankees in New York.

Monday: Ross vs. St. Louis

Tuesday: Corbin vs. St. Louis

Wednesday: Scherzer vs. St. Louis

Thursday: Off

Friday: Fedde at New York Mets

Saturday: Ross at New York Mets

Sunday: Corbin at New York Mets

April 26: Off

April 27: Scherzer vs. Toronto (in Dunedin, Fla.)

April 28: Fedde vs. Toronto (in Dunedin, Fla.)

April 29: Off

April 30: Ross vs. Miami

May 1: Corbin vs. Miami

May 2: Scherzer vs. Miami

May 3: Off

May 4: Fedde vs. Atlanta

May 5: Ross vs. Atlanta

May 6: Corbin vs. Atlanta

May 7: Scherzer at New York Yankees

May 8: Need another starter to keep everyone on regular rest

So that’s how the Nationals could get by with four starters. A more likely scenario is that Lester is back before May 8, meaning Scherzer, Corbin, Ross and Fedde could occasionally get an extra day between outings. Lester, 37, was signed in January to be the fourth starter. He missed some of spring training after undergoing surgery to remove one of his parathyroid glands. Then he was sidelined to begin the season because he either tested positive for the coronavirus or was exposed to an infected teammate.

The lefty threw 49 pitches in three innings of a simulated game Thursday. If he juices that pitch count Tuesday, when a jump is expected, he could be close to rejoining the Nationals. Martinez hopes for him to log five innings and around 85 pitches.

There are, of course, factors to consider beyond Lester and the possibility of a four-man rotation. After giving up 15 earned runs in 6⅓ innings to start the year, Corbin has become a wild card. The severity of Strasburg’s inflammation is a relative unknown. And the Nationals have other depth starters in Ben Braymer, Rogelio Armenteros, Seth Romero and Steven Fuentes, who are on the 40-man roster and at the alternate site.

But it was telling that Espino got plugged into Strasburg’s spot. Martinez offered that Armenteros and Braymer had thrown too recently in Fredericksburg. Romero and Fuentes have never made a major league start (and Fuentes, 23, has yet to debut). The rotation depth has been thinned by injuries and having Voth in the bullpen.

Another quick fix would be to stretch out Voth to replace Strasburg. That way, he would fill Strasburg’s turn, Fedde would have Lester’s, and the Nationals could slide Lester in soon, probably making Voth a reliever again. Or, as shown above, the Nationals could push ahead with four starters this week, and next week, and even for most of the week after that.

There isn’t a ton of risk involved. They could gain a reliever, aiding what is already an overworked bullpen. They would just have to buck convention a bit.