VIERA, Fla. — The Nationals have serious interest in Cuban right-handed pitcher Yadier Alvarez, according to a person familiar with the situation. The 18-year-old burst onto the international market over the past few months, emerging as a top pitching prospect. Alvarez, a shortstop converted to pitcher, is raw but has a fastball that has been clocked in the high 90s, along with a good slider and change-up.

Alvarez, who has been listed at 6-foot-3, 175 pounds, has been throwing in front of scouts in the Dominican Republic. He has not pitched for Serie Nacional, the top league in Cuba, and has little national team experience. According to Baseball America, Alvarez has established residency in Haiti.

Even though the Nationals’ organizational strength is pitching, and they have young arms pushing toward the majors soon, there’s no such thing as too much. Pitchers break down. Prospects don’t always pan out. They can be used a trade chips. The Nationals like Alvarez’s frame and stuff. His fastball has hit as high as 99 mph.

Because Alvarez is under 23 and hasn’t played in a Cuban professional league for at least five seasons, he is subject to international signing limits. It is unclear, however, when Alvarez will be eligible to sign. He still must be cleared as a free agent by MLB and/or the U.S. government. According to FanGraphs.com, Alvarez is seeking a waiver that would allow him to sign before July 2, the first day of the 2015-16 international signing period. He missed the deadline for the 2014-15 period because he was in Cuba.

Alvarez is expected to command a sizable signing bonus, enough to incur a penalty. Any team that exceeds their bonus pool will be penalized 100 percent tax on their bonus pool overage and be prohibited from signing any pool-eligible player for more than $300,000 during the next two signing periods. Among the teams that have already incurred penalties this period: Yankees, Red Sox, Diamondbacks, Angels and Rays. In other words, those teams wouldn’t be suitors for Alvarez after July 2.

Along with the Red Sox, the Dodgers have been very aggressive in the Cuban market, evidenced by their deals for Yasiel Puig, Erisbel Arruebarrena, Alex Guerrero, Pablo Millan Fernandez and, now, Hector Olivera. According to MLB.com, which first mentioned the Nationals’ interest, Alvarez has also drawn interest from the Rangers, Giants and Dodgers, who are believed to be strong suitors.

The Nationals’ 2015-16 international bonus pool is $1.985 million, the second-smallest in MLB, according to Baseball America. During the current international signing period, the Nationals have a $2.08 million pool. Over the years, the Nationals have rebuilt the center of their international operation (their Dominican presence), and have relied on scouting to find less-heralded players and turn them into prospects with a strong development system, such as Wilmer Difo and Reynaldo Lopez.