With so many last-minute changes to the Survivor Series card, it opens up the floor to all sorts of rumors heading into the pay-per-view.

The Survivor Series has always been a pay-per-view where the unexpected often happens. It's the event that has included the debuts of some of the biggest stars in the industry, from The Undertaker to The Shield and with a team format for many of the matches, the card lends itself to a few surprises. This year, things might be a touch more chaotic as the card itself underwent a major shift in personnel from just a few days ago.

AJ Styles is no longer in the main event as the Heavyweight Champion, Daniel Bryan has instead taken his place versus Brock Lesnar. Becky Lynch is out because she wasn't medically cleared to wrestle after taking a stiff punch from Nia Jax and both the men's and women's team matches saw new members added, with one team's roster not even complete.

Here are the biggest rumors heading into Sunday's WWE Survivor Series.

WWE Sending a Message to Unsafe Competitors?

In the latest Wrestling Observer Newsletter, Dave Meltzer notes he’s heard stories of WWE being frustrated with talents like Brock Lesnar and Nia Jax for being potentially unsafe in the ring. Lesnar recently suplexed Sunil Singh on his head and Jax, of course, is responsible for knocking Becky Lynch from the show after clocking her with a stiff fist and breaking a number of bones in her face.

There are questions regarding whether or not WWE will use a show like Survivor Series to send a message to these talents that if they can't be safe with their opponents, they can forget about being pushed. It will be interesting to see if a double-standard is set too. For example, will Lesnar get pushed while Jax does not?

Chris Jericho recently said about Jax on his podcast, "She did knock the f__k outta Becky Lynch, so maybe she might get a little office heat for that." Jericho's co-hosts believed Jax would not be winning at Survivor Series because of it.

Related: Vince McMahon & Ronda Rousey Think Match With Becky Lynch At WrestleMania Is Best For Business

Nikki Cross To Replace Charlotte

via wwe.com

When Charlotte was taken off of the SmackDown Live Women's team and inserted into the match with Ronda Rousey last minute, a spot opened up and no competitor was officially named to replace her. Speculation is that spot will go to Nikki Cross of SAnitY.

Cross is more than ready having made her WWE main roster debut just last week when WWE was in Manchester. She'll also be in town that weekend as part of the NXT crew who will be holding Takeover: War Games II.

Related: Nia Jax Faces Major Backstage Frustration After Becky Lynch Injury

Four Horsewomen Setup

via Wrestling Inc.

There is some speculation that the hug Becky Lynch gave to Charlotte wasn't just a spur of the moment thing in the ring on Tuesday. This was WWE's way of teasing the introduction of a Four Horsewomen of WWE versus Four Horsewomen of MMA feud. Survivor Series may lay the groundwork for that eventual clash.

It was originally believed Survivor Series might be the place where that match happened but obviously, plans changed. Could WWE be working its way towards that match up now?

Related: Dusty Rhodes’ Last Tweet Sent Praise To Becky Lynch

Baron Corbin To Cost Team Raw The Win

via wwe.com

If you listened to the wording during the segment on Raw that included Braun Strowman and Stephanie McMahon, you probably heard McMahon specifically say Strowman could only get his hands on Corbin if he helped Team Raw beat Team SmackDown. Clearly, that's not a good result for Corbin should that come to pass.

Speculation is that Corbin will cost Team Raw the win, saving himself from Strowman but making himself an enemy of McMahon in the process.

Related: Raw Recap, Reactions, & Biggest Moments- Run, Corbin, Run

AJ Styles To Interfere

via wwe.com

It makes sense from so many angles that AJ Styles will get involved somehow in the Daniel Bryan vs. Brock Lesnar match. WWE can't be too keen having either Bryan or Lesnar take the loss and Styles certainly has some unfinished business with Bryan after what went down on Tuesday.

This is the easiest way to save face for all the men involved, especially when you consider Bryan vs Lesnar was supposed to be a dream match with tons of promotion. Clearly, that didn't happen here.

Related: WWE Officially Announces Lesnar Vs Styles II At Survivor Series

Shane McMahon Goes Heel

via wwe.com

Would WWE consider turning McMahon heel after turning Daniel Bryan? There was buzz his win at Crown Jewel and calling himself the 'Best in the World' might trigger a turn but that would be two big names in a matter of days making massive changes.

If WWE goes ahead with it anyway, Shane could turn on his own team and targeting Rey Mysterio. What might also be interesting is that a heel turn for Shane could lead to a babyface turn for The Miz.

Next: Daniel Bryan Pushed WWE To Go Through With Unexpected Heel Turn Before Survivor Series