As officers spoke with the man, 22, "an electronic control device was deployed and the man was arrested," according to a police spokesperson. The rookie was taken directly to the Milwaukee County Jail.
"The circumstances of the incident and the use of force are currently being reviewed by the Department," police say.
There's no word yet on exactly what caused the interaction between Brown and police to escalate.
Surveillance video shared with TODAY'S TMJ4 shows a large police response at the Walgreens after Brown was tased.
Brown, who played college ball for Southern Methodist University, was drafted by the Bucks in the second round of the 2017 NBA draft. He has played in 21 games, two as a starter, during his time in Milwaukee.
BREAKING FROM @Bucks on rookie Sterling Brown’s arrest. “We are aware of the situation with Sterling Brown and are looking into it.”