According to Patrick Reusse of the Star Tribune, an anonymous Chicago media source said Butler began seeing himself as a star once he started to hang out with Wahlberg. The report added: "The feeling in Chicago was that Butler's game stopped growing three, four years ago, as his head grew ever larger."
Per Reusse, the friendship between Butler and Wahlberg began in 2013 when Wahlberg was filming Transformers in Chicago.
Wahlberg played some pickup basketball at the Chicago Bulls' practice facility, and he began spending time with Butler from there.
Reusse noted that Butler's ego became such a distraction amid the burgeoning friendship in Chicago that the Bulls decided to trade him to Minnesota in June 2017.
Butler was reunited with former Bulls head coach Tom Thibodeau, but Thibs reportedly wasn't getting the same player who worked so hard to go from a 30th overall pick to a four-time All-Star.
Reusse referred to Butler as an "egomaniac" who didn't want to share the spotlight with the likes of Karl-Anthony Towns and Andrew Wiggins.
That seemingly boiled over Wednesday when Butler returned to practice for the T-Wolves amid his public trade demands.
According to ESPN's Adrian Wojnarowski, Butler talked trash to Towns, Wiggins, Thibodeau and general manager Scott Layden throughout the practice.
At one point, Butler reportedly said, "You f--king need me, Scott. You can't win without me."
Given how uncomfortable the atmosphere surrounding the practice was, it seems like the only resolution is a trade with the start of the regular season just one week away.