Who cares how fast Pettersson is when he can't stay on his feet. He is so easy to knock off the puck. I've never seen a bonafide NHL player fall as many times as he does in one game.
Send down Chiasson and bring up Lockwood is what I would do. Who cares if we lose him on waivers. The guy is literally useless 5 on 5 and barely effective on the PP (he's not even on either units now).