Annette Alvarado-Bernal, of Puerto Rico, buys a Strasburg tank top for a visiting family member at Nationals Stadium on Friday. "I have my own," says Ms. Alvarado-Bernal, who adds she is a huge Strasburg fan, but "I'm recruiting more."

Annette Alvarado-Bernal, of Puerto Rico, buys a Strasburg tank top for a visiting family member at Nationals Stadium on Friday. "I have my own," says Ms. Alvarado-Bernal, who adds she is a huge Strasburg fan, but "I'm recruiting more."