#7 Xavier Woods
Xavier Woods, one of the three members of The New Day, is currently out of action due to an Achilles injury, which will keep him on the sidelines for a long time. He suffered an injury back in October during a live event, and he could be out for between 6 and 12 months.
He won't be a part of Super ShowDown, but his New Day brethren, Big E and Kofi Kingston will be a part of the show.They will put their SmackDown Tag Team titles on the line against The Miz and John Morrison.
#6 Jeff Hardy
Jeff Hardy is another Superstar who has been out of action, having suffered an injury back in April. Recent reports have indicated that Hardy will be back to the Performance Center, which indicates that his injury is healing, but the Super ShowDown show may come too soon.
Hardy's contract doesn't expire for a while, which means that he should return this year, perhaps after WrestleMania, in April.