Wojnarowski added Butler spent practice "verbally challenging teammates, coaches and [the] front office," and at times specifically targeted head coach Tom Thibodeau, general manager Scott Layden, and teammates Karl-Anthony Towns and Andrew Wiggins.
Sources told Wojnarowski that Butler yelled in Layden's direction, "you (bleeping) need me. You can't win without me."
Darth Amin reported on ESPN's The Jump (h/t Miami Heat Beat) that Butler played with the third-string players on the Timberwolves and beat the starters in a scrimmage. Wojnarowski detailed the scene after the scrimmage:
Adrian Wojnarowski @wojespn
A lot of Minnesota players left Timberwolves practice today energized by Butler's performance, mesmerized with him taking end-of-the-bench players and running the table on the regulars, sources said. At the end, he marched out like if a mic drop. Butler delivered a tour de force.
"It was bad," one Timberwolves staff member told RealGM's Keith Smith. "Guys come in angry, having bad days all the time. This was as bad as I've ever seen a practice in my years in the NBA."
The Athletic's Shams Charania reported on Tuesday that Butler returned to Minnesota to reiterate his trade stance during a meeting with Thibodeau.
Butler's relationship with Wiggins and Towns has reportedly been a source of conflict within the Timberwolves' locker room dating back to last season.
Joe Cowley of the Chicago Sun-Times reported over the summer that Butler was often frustrated by the "nonchalant attitudes of younger teammates—specifically Karl-Anthony Towns" during the 2017-18 season.
Butler averaged a team-high 22.2 points in 59 games last season. The Timberwolves finished 47-35 before losing to the Houston Rockets in the first round of the playoffs.