Gallen has blasted Odemwingie's advisors over the controversial affair.
He said: "It's a farce. The club are going to fine him and I can't see how he's going to play again for West Brom.
"What are the fans going to do when he comes on to the pitch? They're going to go absolutely crackers.
"He's made it obvious over the last couple of weeks that he wants to leave. West Brom have stood very firm. Usually in these situations it's always the selling club that loses out, but West Brom have held their own.
"The problem is they now have an unhappy player and some unhappy supporters against him.
"They should have taken the money. What's the point of having a player who doesn't want to play for the club and is going to cause problems in the dressing room and with the manager? They should have let QPR have him."
Gallen, 37, who played 366 times for Rangers, added: "His agent has told him to go and force the move, which is really bad advice. He's a West Brom player and you can't just turn up at a football club and expect to sign for them.
"He's now got to face the music."