#4 Cain Velasquez
We put Cain Velasquez on top of this list because (a) the former UFC Champion will probably return as a SmackDown Superstar and (b) he is a mainstream name. Velasquez debut match happened against Brock Lesnar and he lost in a matter of minutes.
He has been on the sidelines due to a knee injury and he could be returning sooner rather than later. Reigns vs Velasquez can be a blockbuster rivalry if booked correctly. Both Superstars have lost against Brock Lesnar and both have beaten him too. Besides, both are popular names. Their rivalry would surely generate high viewership for SmackDown on FOX.
However, it’ll be interesting to see if Vince McMahon will allow Velasquez to take on The Big Dog. There were some rumors that WWE management has lost faith in him, but those could be false. Yes, we know that a rivalry between these two seems pretty unlikely at this moment but is there anything in WWE as impossible? No, right?