Vince McMahon announced a new “Wild Card” rule on Monday’s episode of RAW, which will allow four RAW stars to appear on SmackDown Live on any given week, along with four SmackDown talents appearing on RAW. McMahon noted that the new rule would be limited to four stars, otherwise he’ll “suspend somebody” or fire them.

Five SmackDown stars actually appeared on RAW, with Roman Reigns, Daniel Bryan, Kofi Kingston, Lars Sullivan and Elias. McMahon said that Elias didn’t count as one of the four talents that can appear because he was with Shane McMahon.

Most of the RAW roster would be unable to appear on SmackDown Live tonight because they are heading overseas for the European tour, which starts on Wednesday in Belfast, Northern Ireland, and runs through Friday, May 17th in Cardiff, Wales. The SmackDown side of the tour kicks off on Thursday in Dublin, Ireland and ends on Friday, May 17th in Berlin, Germany.

The shows on the tour will feature the rosters before the Superstar Shakeup last month. Reigns will be at the RAW live events, and he is not scheduled to appear on SmackDown Live tonight.

AJ Styles and Samoa Joe are booked for the SmackDown live events on the European tour, so both men could appear on SmackDown Live tonight. Other RAW stars that are booked on the SmackDown shows are The Usos and Naomi. AJ teased going to SmackDown with some friends, so Karl Anderson and Luke Gallows are also possibilities to appear tonight.

As we previously reported, tonight’s SmackDown will also feature new SmackDown Tag Team Champions being crowned by Shane McMahon, as well as Ali vs. Andrade and a six-woman match with Charlotte Flair, Mandy Rose & Sonya Deville facing Bayley, Ember Moon & Carmella. Kevin Owens is slated to open the show to respond to WWE Champion Kofi Kingston’s attack from last week.