Last month, Urbina and a group of men allegedly attacked five workers with machetes and poured gasoline on them in an attempt to set them on fire. All five were injured, some of them with cuts and one with burns on the back and right arm, police said.
Urbina, who was detained late Monday, has insisted he had nothing to do with the violence at his family's ranch on Oct. 16.
"Everything will be cleared up soon and people will know the truth," Urbina said from his cell at a police station. "Right now we aren't going to do anything to deny things that aren't true."
The authorities said Urbina would be formally charged once he appears before a judge, and Urbina said he understood that hearing could be held Tuesday.
Urbina's lawyer, Jose Luis Tamayo, said the pitcher was sleeping at the time of the incident and was not involved. One victim, Argenis Farias, has accused Urbina of being among the attackers.
Urbina was traded from Detroit to Philadelphia in the middle of last season. The reliever became a free agent after the season ended.
"This, of course, can in some way hurt his career as a professional ballplayer, and all will depend on the way in which he is brought before justice," defense lawyer Jose Luis Tamayo said.