Washington’s Brian Broderick pitches to St. Louis’s Skip Schumaker in the fourth inning of Friday’s spring training game in Viiera, Fla. (DAVID GOLDMAN/ASSOCIATED PRESS)

On Friday afternoon, Brian Broderick strode to the mound of Space Coast Stadium and provided the St. Louis Cardinals with a glimpse of what could have been theirs. He threw 17 pitches, 12 of them strikes, almost all of them sinking fastballs in the low 90s, the kind of pitch that makes a hitter wonder how he made an out while he trudges back to the dugout.

Broderick walked off the mound having allowed no runs, which is what he has done in just about all of his performances with the Washington Nationals. Broderick felt “a little weird” facing batters from the Cardinals, the team that left him exposed this winter to the Rule 5 draft. The Nationals chose him in the second round, a decision that drew little attention until he started getting out pretty much everyone he faced this spring.

Broderick, 24, arrived at Nationals spring training, his first major league camp, as an afterthought. Over the past month he has asserted himself as a possible, if not likely, member of the Nationals’ opening day roster. After tossing another scoreless inning Friday against his old team, Broderick has allowed one earned run in 92 / 3 innings. If you chose the three most impressive Nationals pitchers all spring, Broderick would be one of them.

“He’s forcing the issue,” Manager Jim Riggleman said. “And I’m glad to see he’s doing it.”

This December, Broderick heard the Nationals select him during the Rule 5 draft and blurted, “Did they really just say my name?” He had never pitched above Class AA, and the Cardinals had decided to make him available to 29 other teams by not adding him to their 40-man roster after his fourth minor league season. Now, the Nationals had spent $50,000 in order to guarantee him a spot on their 25-man roster or risk losing him back to the Cardinals.

Nationals scouts, particularly front-office special assistant Deric Ladnier, had watched Broderick all of last season and during his stint in the Arizona Fall League, during which time, incidentally, he struck out Bryce Harper. He rarely walked anyone and understood how to create contact without allowing hits.

“He is a strike-thrower that gets groundballs,” Ladnier said in a phone conversation. “Any guy that can pound the zone and mix his pitches like he does and induce soft contact, all those things are what you’re looking for in a major league pitcher.”

Last year, at Class AA Springfield, Broderick went 11-2 with a 2.77 ERA. He struck out just 4.9 batters per nine innings but walked only 1.3, the fourth-best rate in the Texas League. “He’s got good stuff,” said Nationals minor league catcher Derek Norris, who watched Broderick in the Fall League and caught him early in spring.

Broderick relies more on command and competitiveness than stuff. He worked with Springfield pitching coach Dennis Martinez, the former major leaguer, who told him to “be a bulldog” on the mound. He improved his sinker by changing his grip, bringing his index finger and middle finger so close on the middle of the ball that they practically touch.

Broderick also worked on his arm angle in order to take full advantage of his size. His sinker is especially effective when it darts down from his 6-foot-6-inch frame to the batter’s knee.

“He uses his leverage real well,” said Cardinals bullpen coach Derek Lilliquist, who served as the organization’s pitching coordinator during Broderick’s tenure. “You look at his stuff, and it doesn’t really light you up in terms of his arm strength. But he gets outs. He’s a good competitor. He’s got his head screwed on straight. By today’s standards, you may say his stuff is average, a tick above average. But he’s got some heart.”

Broderick’s barrage of groundballs has helped him allow only four hits and two walks despite just four strikeouts in his 92 / 3 innings. Though Broderick has primarily been a starter during his minor league career, the Nationals are considering him only as a reliever at the moment.

Broderick has made 20 relief appearances in his minor league career, and he sometimes pitched out of the bullpen, occasionally as a closer, at Mesa Junior College and Grand Canyon University. “It’s not going to be like, ‘Oh my God, I’m in the bullpen,’ ”Broderick said. “It’s, ‘I got to take it and go with it.’ ”

For a while this season, Broderick dealt with an uncertain future. Now, with opening day less than two weeks away, he has allowed himself to think about what it would be feel like to make the Nationals, to line up on the base line and tip his cap on opening day.

“Who wouldn’t?” he asked. “I’m trying to go out there and make an impression — and stick with the club.”