Convicted murderer Aaron Hernandez is getting himself into trouble behind bars already.

Hernandez was reportedly part of a prison fight on Monday at the Souza-Baranowski Correctional Center in Lancaster. Sources say the former Patriots tight end played lookout for an inmate who went into another prisoner's cell and initiated the brawl.

Sources tell CNN the fight was believed to be gang-related.

All three men are being disciplined over the incident, but a spokesman for the Massachusetts Department of Correction declined to give any specifics saying regulations forbid divulging information of that kind about inmates.

This is actually Hernandez's second fight since being placed behind bars. While awaiting trial he and another detainee were involved in a brawl at Bristol County jail.

Hernandez does have another trial looming for deaths that occurred in July 2002. He may have a trial date for the double-murder charges he's facing set on Thursday.