The knuckle at the base of Max Scherzer’s right ring finger became the most analyzed joint in the Washington Nationals‘ clubhouse on Thursday, knocking Stephen Strasburg’s right elbow out of its familiar spotlight, and delivering an unexpected blow to the early-season stability of the Nationals’ rotation.

The most recent MRI results of Scherzer’s finger showed the stress fracture that developed late last season is, as he put it, “essentially healed.” But the reigning National League Cy Young Award winner was not ready to pitch off a mound during the first official workout of the Nationals’ season. He might not be ready for Opening Day, either.

“I don’t even want to comment on [Opening Day], because I don’t even know what I’m going to be able to do or not,” said Scherzer, who has been the Nationals’ Opening Day starter the past two years. “It’d be unfair for me to even project or even talk about that.”

While Strasburg marched through the first official workout of the Nationals’ season uninhibited, Scherzer was treading carefully, relegated to a high-intensity game of catch with rehabbing lefty Tim Collins — the only other pitcher in camp who cannot participate fully. As Strasburg threw change-ups and sliders and honed two-seam fastballs, Scherzer was heartened by the fact that he could play catch with a baseball. He spent the winter throwing tennis and lacrosse balls to keep his arm in shape, because the baseball was too big for his injured finger to grip. He modified his grip again Thursday.

“As this fracture continues to heal, as the symptoms continue to alleviate, as we get treatment on everything, I’ll be able to work back into all my grips and obviously get back on the mound,” Scherzer said. “But right now it’s just getting back out there, throwing a baseball and getting my arm in shape.”

Scherzer first felt trouble after a start against the Baltimore Orioles on Aug. 25. Doctors diagnosed a finger sprain. Four days later, when he warmed up ahead of his next start, Scherzer found he could pitch through the pain. With the Nationals headed to the playoffs, he decided to do so. Put under continued pressure, the sprain turned into a stress fracture.

“I said, ‘I want to pitch.’ If I can go out there and compete at 100 percent and not make any excuses, then I’m going to go out there and do that,” Scherzer said. “The fact that it morphed to a fracture, that’s just the cost of doing business.”

Scherzer expected the sprain to heal with regular rest in the offseason. But the symptoms did not improve by December, when another MRI exam revealed the fracture. A month later, the fracture still had not healed, so he told Team USA Manager Jim Leyland he would not be able to pitch in the World Baseball Classic.

In the meantime, he tried to give the finger time to rest, which meant cutting back on his usual throwing program. Until he can grip a baseball properly, he cannot resume his usual spring training regimen. Until he can start throwing like he normally does, Scherzer cannot build the kind of arm strength he needs.

“I was able to keep some functionality in my arm,” Scherzer said. “Elbow, shoulder, lat, that chain all that feels good and is on pace to take on an expedited throwing program.”

An expedited throwing program, begun soon, could certainly make Scherzer ready for Opening Day. A slow-moving throwing program, started a week from now, would probably still have him ready sometime in April. As Dusty Baker pointed out, a pesky knuckle injury is far more appealing than elbow or shoulder trouble, if one had to choose between them. He also pointed out that fewer innings for Scherzer early, even low-stress spring training innings, could leave Scherzer stronger late in the season.

Still, the Nationals now must make plans in the meantime. A fully healthy Strasburg would help fill Scherzer’s void. He threw for 10 minutes in the bullpen, mixing all his pitches and working on a two-seamer with pitching coach Mike Maddux, before going through a full day of pitcher fielding practice and conditioning.

“I don’t think [Day One]’s been the issue in past years,” Strasburg said. “Minus my Tommy John year, I’ve always been here Day One. The question is Day 162 — or whatever it is with those off days.”

If Scherzer cannot pitch by Opening Day, Strasburg probably will assume those duties. The Nationals will not lack a qualified Opening Day starter.

But a prolonged Scherzer absence will require them to find a fifth starter behind Strasburg, Tanner Roark, Gio Gonzalez, and Joe Ross. A.J. Cole, who made eight starts late last year, added 15 pounds this offseason, and says he feels much stronger. Austin Voth, who ranked among the International League’s ERA leaders last year for Class AAA Syracuse, is in big-league camp for the second time. With Lucas Giolito and Reynaldo Lopez gone, Voth’s path to the majors could be clearer.

“We’re always looking for a surprise guy to emerge,” Baker said. “Is that surprise person, whoever that is, is that a temporary situation? Or could they lodge themselves solidly in our rotation?”

If all goes well with Scherzer, no one will have to lodge themselves anywhere. Scherzer has shown great self-awareness with injuries during his Nationals tenure and has not missed a start. The Nationals had to push him back a few days early in the 2015 season when he injured his finger bunting in April. But he has pitched at least 200 innings in each of the past four seasons, despite nicks and bruises, and making sure pushing through one injury didn’t lead to another. While pushing through the finger sprain led to the fracture, it did not — and Scherzer was adamant about this — lead to any elbow or shoulder trouble. If he rushes through a throwing program, it could.

“Sometimes the only healer is time,” Baker said. “We’d like to rush it, but you’d hate to have to rush it and have this lead to something else. He’s too valuable and too important of a guy.”