#3 Sami Zayn

Sami Zayn is perhaps someone who has terrible luck. While his good friend and former NXT rival Kevin Owens has scaled great heights on the main roster, Zayn hasn't had the same luck owing to injury and some poor storylines. Zayn is currently out due to injury, but WWE announced last month that Zayn and Owens would return to the WWE.
Bryan Alvarez of the Wrestling Observer recently said that Zayn would not be back in January and that we could see him in February. “Kevin Owens and Sami Zayn – they’re not gonna be back probably until February I would guess. Maybe they’ll be back a little early. But when they were making all of their announcements, that was something else they could tell the fans," said Alvarez.
Sting in WWE once again? More details HERE
Also Read: 5 Superstars who should not win WWE Men's Royal Rumble 2019
But WWE is known to spring a surprise, and maybe we could see Zayn interfere briefly and set-up a feud without even actually wrestling in the ring, which could be an option if he's not medically cleared yet.