#2 Sami Zayn
If anybody out there is going to be challenging Samoa Joe, the best bet right now is Sami Zayn.
Since the match against Seth Rollins at Fastlane is no longer going to happen, it looks as though Joe is being positioned to beat up Zayn instead, but while that might come off as just a replacement filler match to take up his time at the event, there may be more implications to it than on the surface.
A top AEW star just called one of his colleagues 'spoiled' and 'narcissistic' HERE.
It's a much bigger deal for Joe to miss out on the WrestleMania card than it is for him to skip out on Fastlane, so if WWE doesn't have an idea of what to do with him for both shows and has to pick, Fastlane needs to be sacrificed, meaning a match between Joe and Zayn would be put off.
They've teased that Zayn will receive a title shot for the United States Championship against Chris Jericho, and with Jeri-KO broken up, there's a chance Kevin Owens comes out to cost Jericho the match. If that happens, Zayn would become the new United States champion, which then boosts his star power for WrestleMania.
While Jericho is off facing Owens either for the Universal Championship or just in a standard grudge match, Zayn could have a bone to pick with Joe for the way he attacked him, leading to a United States Championship match between the two at WrestleMania where Joe most likely would take the title from Zayn.
This would give Joe a prominent spot on the Raw roster without encroaching into the Universal Championship picture, as that would either consist of a heel in Kevin Owens, a part-time heel in Brock Lesnar or a part-time babyface in Goldberg—none of which seem like the next obvious feud to invest in for Samoa Joe. In comparison, Zayn is beloved by the crowd and someone who can be served up to lose to Joe so he can look strong while being booed.