The origins of the Great Todd Frazier-Adam Eaton Feud are still a mystery, but Tuesday night gave some insight to what started it all.

Former Chicago White Sox manager Ozzie Guillen, who figures to still have an idea of what’s going on in the clubhouse as an NBC Sports Chicago analyst, weighed in.

“Eaton, nobody liked you in a White Sox uniform in the clubhouse, OK?” Guillen said. “That’s what I know.”

Guillen managed the club from 2004-2011, while Eaton was in town from 2014-2016. Frazier spent 2016 and half of 2017 in Chicago.

Whatever drove the players to opposite sides of the White Sox’ locker room clearly carried over into this week’s Mets-Nationals series, where the two have spent plenty of time sniping at one another, on and off the field. They appeared to speak to one another in the outfield ahead of Tuesday’s tilt, though it remains to be seen if they were talking things out or simply reliving their Windy City days.