Brown, 24, has missed the past 18 games due to an upper-body injury.
"Going down and playing some games is going to help," Blues Head Coach Craig Berube said. "He needs the game action. That will help him be more prepared when he's ready to go up here."
The 6-foot-6, 218-pound forward has dressed in five games with the Blues this season.
A St. Louis native, Brown was acquired by the Blues via trade from the Ottawa Senators on September 18, 2020. Overall, he has recorded 20 points (five goals, 15 assists) and 14 penalty minutes in 74 career NHL regular-season games.