O'Brien has no goals and three assists in 45 games played, as well as a total of 58 penalty minutes this season. He's been pretty terrible for every Flame he's been paired with, and while he's had success in past years he is not helping this Flames team at all. As Kent Wilson noted at FlamesNation, O'Brien only played five minutes versus the Predators but was -3, which is ... real bad.
The Flames haven't announced any corresponding moves yet but we'll update when news comes down. Update: Chris Breen has been called up from Abbotsford. Ari wrote more about the decision: Shuffling the deck chairs on defence: Breen replaces O'Brien.