The stakes of Monday’s bullpen session were clear: If Max Scherzer’s groin felt fine during it, he could have faced the Pittsburgh Pirates at Nationals Park on Wednesday. But because it didn’t, and Scherzer still couldn’t fully push off his right leg, the Washington Nationals’ ace will skip his turn and possibly go on the 10-day injured list.

The Nationals could backdate Scherzer’s IL stint to Saturday, making it so he would miss only one start. Scherzer tweaked his groin in the first inning of a start against the San Francisco Giants on Friday. An MRI exam revealed inflammation instead of a muscle strain, and Scherzer considered that the best-case scenario.

After the Nationals beat the Pirates, 3-2, on Monday, Manager Dave Martinez said he still hadn’t made a decision about Wednesday’s starter. He added that Scherzer is unlikely to go but could be held off the IL if he keeps improving. That would allow the Nationals to bump back his next start, perhaps to see the New York Mets at home this weekend.

Martinez expected Scherzer to throw 31 pitches in Wednesday’s bullpen session. Scherzer only managed 10. Martinez had said in the afternoon that he was split between pushing Scherzer and resting him for another week. With a 28-35 record after Monday’s series-opening win over the Pirates, the Nationals rightfully see this as a critical stretch. Yet that doesn’t mean they should put their best pitcher at risk of further injury.

“I would injure this worse. That’s the risk you’re taking trying to pitch through this,” Scherzer said Monday. “This is just something you can’t pitch through. I’ve pitched through a lot of other things, found a way to do a lot of other stuff. But this one you just can’t get around.”

So how does he calculate being smart with wanting to be on the mound?

“It’s everything. It’s the time of year. Understanding where you’re at, what you’re actually able to do. You take everything into account,” Scherzer explained. “The other risk in this is, if you don’t pitch, you take too much time off from pitching, then your arm can get tired. And as you try to ramp back up, you can hurt your shoulder. You want to get back out there. There’s risk to not pitching. So there was an incentive for me to go ahead and make the start. But it’s just not worth it.”

Reliever Paolo Espino has a good chance to fill in Wednesday. After Scherzer exited at 12 pitches Friday, Espino entered to throw 50 and hold the Giants to one run. He is thus on schedule to throw three to five innings in the series finale with the Pirates. Espino took batting practice with the starting pitchers Monday, and Martinez acknowledged it was because he may have to hit this week.

Scherzer, who turns 37 next month, left a 2020 start with a tweaked right hamstring. Otherwise, he spent 2019 dealing with back and shoulder strains, not any lower-body issues. And before that, Scherzer made 30 or more starts in 10 consecutive seasons. He remains on pace to do so again this year. But that will depend on listening to his body now, pitching a bit later.

“I’m happy with the progress. For three straight days, I’ve made progress on it,” Scherzer said. “I’m able to do something more every single day. That’s why I said I might be able to make it in time for Wednesday, but you just can’t. Might’s not a good word in June.”

Read more on the Nationals and MLB: