(Photo by John McDonnell/The Washington Post)

Saturday afternoon, Doug Fister returned to major league action 20 days after he first felt a twinge in his elbow. He could have joined the army of unfortunate pitchers who have snapped a ligament or frayed a muscle this spring, leaving their teams scrambling for a replacement. Fister’s tests returned clean. Inflammation receded from his elbow. Throwing sessions passed without incident. The scourge spared the Nationals.

“With all that’s happened this spring with all these starting pitchers, it’s scary for any club,” Manager Matt Williams said. “The MRI results were a relief initially. The fact that he’s going through a pretty heavy schedule outside of games with throwing. He feels good out of that. That’s all positive signs.”

The most positive sign came Saturday. In his second Grapefruit League start, the Nationals had planned to let Fister throw 45 pitches over three innings. He carved the Marlins’ split-squad lineup for three innings, and felt so strong he emerged for the fourth and recorded two more outs. Marcel Ozuna whiffed at Fister’s 47th and final pitch.

In his 3 2/3 scoreless innings, Fister yielded two hits, hit one batter and struck out four. He induced five groundball outs, including a double-play ball. According to one scout’s radar gun, Fister’s sinker hummed between 89 and 91 mph – faster than his average velocity in 2013. They darted with his trademark heavy sink. “Bowling balls,” the scout said.

“It’s not knocking a little bit of rust off, but everything felt very good,” Fister said. “It’s a relief when you get out there and feel good. All the work we’ve been putting in, trainers and pitching coaches and everybody, it’s paying off and we’re on the right track.”

Fister threw like a pitcher ready for season, pending the accumulation of more arm strength. He said he concerns himself more with building innings than soreness. He felt no discomfort following his outing. Afterward, though, he was not prepared to make any pronouncements about his readiness for the season.

“Can’t get ahead of ourselves,” Fister said. “We just got to wait for another five days and get ready for it.”

Since the early signs portended a quick recovery for Fister, the Nationals have assumed he will take his first turn in the rotation. It could be in the fourth, fifth or sixth game of the season, depending on how much time he needs to build arm strength and how the Nationals’ rotation shakes out. If he starts Game 4, he would make his Nationals debut in their home opener.

Based on Fister’s current schedule, he seems to be aligned for April 6, the Nationals’ sixth game. If he pitches again in five days, he would start the Nationals’ Grapefruit League finale Thursday. He could then throw a simulated game April 1, a day off for the Nationals, setting him up to come back April 6 for his season debut.

During one stretch Saturday, Fister hit Reed Johnson in the lower leg with a sinker, then nearly hit Ty Wigginton in the same spot. Other than that blip, though, Fister showed his usual excellent control. He kept his sinker down in the strike zone, barreling from shin-level to ankle-high.

“Command is coming back,” Fister said. “I’m still working on those kind of things. I’m pleased with where I’m at, but there’s still a long way to go before the season. I’ve got a lot of work in  a little bit of time.”

And will he get that work done?

“Oh, yeah,” Fister said. “It’s not a problem.”