Jax – a former WWE Raw Women’s Champion – has arrived at the arena in San Antonio ahead of the bumper show, reports PWInsider.
The 34-year-old is a rival of both Rousey and Bliss, and there is speculation she could be set to become involved in their Raw Women’s Championship match.
She has been out since Extreme Rules on July 15 rehabbing an injured leg.
Bliss and Jax had clashed in an extreme rules match as the two former friends went to war over the Raw Women’s Championship.
Ronda will take on Bliss tonight after claiming the championship from her with a dominant win at SummerSlam.
“Hell in a Cell kicks off tonight at midnight”
Jax was also reportedly backstage at SummerSlam, but failed to appear on the show.
WWE keep their storylines a closely guarded secret - so there will be no confirmation on Jax’s involvement until the match occurs later tonight.
Ronda was a rival of the star back in May, unsuccessfully challenging her at Money in the Bank for the Raw Women’s Championship.
And Bliss and Jax – famously good friends away from the ring – were involved in a bitter “body shaming” feud leading into WrestleMania 34 – and Jax’s first title win.
Jax claimed the Raw Women’s Championship from Bliss at the mega show after weeks of deeply personal rivalry.
Bliss bullied and embarrassed Jax – targeting her size – but was eventually defeated.
It was that same night Rousey made her WWE in-ring debut alongside Kurt Angle in a mixed tag match against Triple H and Stephanie McMahon.
Rousey’s meteoric rise comes off the back of one of the most celebrated career’s in UFC – officially making her first WWE appearance back in January at the Royal Rumble.
Jax debuted in WWE on NXT where she played a monstrous villain – using her size and strength to brutalise opponents.
She moved up to the main roster in 2016 and was involved in various feuds before becoming a hero back in March during her feud with Bliss.
Away from the ring she also works as a plus sized model, and is a cousin of legendary wrestler Dwayne “The Rock” Johnson.
Hell in a Cell kicks off tonight at midnight – and will be headlined by Roman Reigns vs Braun Strowman with special guest referee Mick Foley.