Rey Mysterio became the new US Champion after defeating Samoa Joe at Money in the Bank in a match which made headlines due to several reasons. Yes, not only did the match abruptly after Joe was left bleeding profusely through his nose courtesy of a seated Swanton from Rey gone wrong, but the 6-1-9 Superstar too suffered a separated shoulder.
With Mysterio getting injured, Joe appeared on the last episode of Raw, demanding Rey to vacate and hand over his US title to him. However, given how actively WWE has been involving Rey's son, Dominic in this feud, creative could use this situation wisely to have him step-in to fight on behalf of his father for the title.
Given how things have unfolded in the feud, it would seem totally apt for Dominic to stand for his father.
Thus, WWE could officially announce a fascinating match between Samoa Joe and Mysterio's son, Dominic for the United Staes Championship at Super ShowDown.