fireballer

今日のThe Daily Yomiuriにあった記事からです。fireballには「火の玉」以外に野球の文脈で「剛速球」という意味があります（『プログレッシブ英和中辞典』小学館）。記事中のfireballerは「剛速球を武器にしている投手」を指しています。（Koyamamoto）

H.S. sensation Otani opts to head to majors
As Japan pro baseball teams prepare for the upcoming amateur draft, they can cross off one of the biggest names on the list of prospects.
Fireballer Shohei Otani of Hanamaki Higashi High School has decided to forego playing in Japan and start his pro career in the major leagues.
"Playing in the United States has been a dream since I entered high school, so I decided to play there," Otani said at a press conference Sunday at the school in Hanamaki, Iwate Prefecture. "I'll start with the minor leagues, but I'll make the majors [in the future]."
http://www.yomiuri.co.jp/dy/sports/T121022002419.htm