Cuba's Frank Alvarez throws ball at heckling spectator during loss to USA

March 20 (UPI) -- Cuba pitcher Frank Alvarez responded to a heckling spectator by throwing a baseball from the bullpen toward him during a loss to the United States in the semifinals of the World Baseball Classic in Miami.

The incident occurred during Team USA's 14-2 win Sunday night at loanDepot park. Video footage of the sequence was posted early Monday on social media.

Alvarez, MLB and representatives from the World Baseball Classic and Cuban team did not immediately respond when asked for comment on the matter.

Alvarez allowed two hits and one run in 2/3 innings. He was in the right field dugout during the sequence with the fan. A man stood up near a railing above the area at the start of the exchange. He leaned over the railing and shouted words down at Alvarez and other members of the Cuban team.

Alvarez then turned around and threw the ball at the man, intending to hit him. The right-handed pitcher, who threw several pitches that eclipsed 90 mph during his mound appearance against the Americans, reached back for more power during his throw at the heckler.

That attempt appeared to sail off-target, as the man continued to yell in his direction. Other fans in the area flinched and ducked when they saw the throw coming into their seating area.

Alvarez did not allow a hit in two innings of work in his first World Baseball Classic appearance. He also logged three strikeouts in that 13-4 win over Panama on March 10 in Taichung, Taiwan.

The 24-year-old pitcher is a member of the Chunichi Dragons of the Japan Wester League. He owned a 3.38 ERA in seven appearances last season.

He previously pitched for Vegueros de Pinar del Rio of the Cuban National Series.

Four men also were arrested and charged with trespassing after they rushed the field during Sunday's game. A large group of protesters also met outside the stadium and voiced opposition for Cuba's participation in the tournament before the game.

Philadelphia Phillies shortstop Trea Turner homered twice and drove in four runs to spark the American power surge Sunday in Miami. St. Louis Cardinals first baseman Paul Goldschmidt also logged four RBIs for Team USA.

The Americans will face Japan or Mexico in the title game Tuesday in Miami.