#1 Dean Ambrose
After successfully reuniting with his former Shield brother Seth Rollins, the duo went on to become the Tag Team Champions at SummerSlam last year. Later in October, the duo reunited with Roman Reigns to reform the Shield, to one of the biggest crowd pops in recent memory.
The much-hyped return was short lived though, as Ambrose sustained a serious tricep injury towards the end of 2018, rendering him unable to compete. On screen, he was written off after being attacked backstage by Samoa Joe. He was recently rumored to be present at WWE's Performance Centre, most probably for physiotherapy, but it is unlikely that he is currently ready to return to the ring.
Got injured in: December 2017
Nature of the injury: Torn Triceps
Timeline of return: Around September 2018