Defenseman Seth Jones suffered an upper body injury in Team USA's 6-3 exhibition loss to Russia last night, that will now officially keep him out for the tournament. Jones' play, along with the unavailability of Justin Faulk, made it pretty likely that he would have made the team's final roster, despite being the youngest player, and only 2013 draft eligible player, at Team USA's camp. I'm sure it was has to be disappointing for Jones, though as a '94 birthdate, he'll still have two more opportunities to play in the World Juniors.
For a group of defensemen that was considered the deepest the United States had ever seen a few years go, the US is going to be bringing a pretty thin, depleted group into this tournament. Jones' unavailability likely opens the door for Jacob Trouba to make the final roster. The final roster will be announced on Thursday morning.