Neal, a 14-year NHL veteran with 869 games of regular-season experience, has played in 19 games for the Blues this season, posting two goals and two assists.
"It's a tough situation for a guy like that who has played a long time in the NHL," Blues Head Coach Craig Berube said of Neal's assignment to the Thunderbirds. "He's still looking to play and compete and be part of a team. I have all the respect in the world for Nealer. He's a great team guy, he works really hard. We'll see what happens."