#3 Roman Reigns vs Seth Rollins (no.1 contender's match)
WWE fans would not want this match to happen but it has a strong possibility of happening. Reports surfaced online that Vince McMahon never had any ideas to do a match between Seth Rollins and Brock Lesnar at WrestleMania 2019.
It was, apparently, Triple H who made the call. Vince might have agreed to this just because of Roman's absence. Now that Roman is back Seth Rollins might turn on him. It might possibly lead to a match between them at Fastlane for the no.1 contender's spot at WM 2019.
Roman might go all the way to headline WrestleMania. It would not be a popular option but given WWE's nature of seizing the moment, it might happen. Roman is receiving huge pop from the crowd and it is a reason enough to get tempted to try this option.
Seth Rollins worked hard the whole year to get a WrestleMania main event. Thus, the decision cannot be expected to receive a positive reaction. It might get a huge fan backlash.