The 20-year-old Dominican right-hander was arrested on a felony assault charge Thursday night after heightening an already dangerous situation by hitting a fan with a ball in the first inning of the visiting Chiefs' 6-5 loss to the Dayton Dragons.
Things got heated in a hurry at Fifth Third Field when Castillo (0-2) beaned Dayton shortstop Zachary Kozart with one on and no outs in the opening frame.
Kozart left the game, but the hostility started to build when Brandon Waring grounded a ball past Castillo toward second baseman Gian Guzman. Castillo and Guzman collided as Waring reached base safely, but Guzman suffered a broken leg and left the contest on a stretcher.
Denis Phipps followed with a two-run double and Devin Mesoraco added a two-RBI base hit to give the Dragons a 4-0 lead. Angel Cabrera, who had lifted the Dragons to a 4-3 victory with a walk-off homer in the bottom of the ninth on Wednesday night, was plunked by Castillo.
An agitated Cabrera took first base and Keltavious Jones grounded into a force play, but the Chiefs took exception to Cabrera's hard slide into shortstop Nate Sampson.
Interim Peoria manager Carmelo Martinez -- filling in for Ryne Sandberg -- came out of the dugout and got into an argument with Dayton skipper, Donnie Scott, who was coaching third. Martinez and Scott appeared to make contact before Castillo inexplicably fired a ball toward the Dragons dugout. The ball ricocheted into the crowd and hit a male fan, causing both benches and bullpens to empty.
Dragons left fielder Brandon Menchaca tackled Castillo from behind as skirmishes broke out all along the third-base line. The fan was taken to an unknown area hospital and his condition was unavailable.
Castillo is expected to be arraigned Friday, but the ramifications from this game will likely be felt by both teams for the remainder of the year, including their final regular-season meeting Friday night.
"Tonight's on-field incident between the field staffs of the Dayton Dragons and Peoria Chiefs was unfortunate and we sincerely wish that it would have not happened," Dayton general manager Gary Mayse said in a team-issued statement.
"We are confident that the footage of tonight's incident will be reviewed by Midwest League President George Spelius and appropriate actions will be taken."
There were 15 ejections issued immediately following the incident. However, umpires went back into the clubhouse and were instructed by Spelius to reinstate all the players and both managers to avoid placing pitchers in the outfield to fill out the lineups. Castillo obviously did not return, and there were no further incidents during the game.
The original ejections for Dayton were: Scott, Justin Reed, Kevyn Feiner, Phipps, Mesoraco and pitchers Henry Arias, Jeremy Horst, Jeff Jeffords and Luis Montano.
Brandon Guyer, Jovan Rosa, Mario Mercedes, Cliff Andersen, Castillo and pitchers Stephen Vento and Audy Santana were sent off for the Chiefs. Martinez, forced into action with Sandberg attending Hall of Fame ceremonies in Cooperstown, N.Y., was also tossed before being reinstated.
Waring singled home a run in the second to give Dayton (20-13) a 5-0 cushion before Peoria mounted a comeback.
Andersen, Jonathan Wyatt and Samson delivered RBI singles in the seventh and Rebel Ridling scored on a wild pitch in the eighth as the Chiefs (21-12) cut the deficit to 5-4.
Cabrera provided some much-needed insurance with an RBI groundout in the bottom of the frame before Peoria again shaved the deficit to one on Rosa's run-scoring double in the top of the ninth.
Derrick Conatser finally ended the contest by recording the final two outs for his first save.
Juan Rafael (1-1) picked up the win in relief, yielding two runs on four hits with seven strikeouts in 5 2/3 innings.
John Torenli is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.