Finn Balor was scheduled to wrestle Shinsuke Nakamura on tonight’s “Smackville” house show on WWE Network, but WWE announced on the show that Balor was not cleared to compete, and said on Twitter that Balor “suffered an undisclosed injury.”
During the week, @FinnBalor suffered an undisclosed injury. @WWE Medical has unfortunately not cleared him for competition tonight at #SMACKVILLE. It is unknown who or if @ShinsukeN defends his title tonight. Stay tuned as we learn more.
— WWE (@WWE) July 28, 2019
According to John Pollock of Post Wrestling, Balor is not injured, but is dealing with a “24-hour bug type situation” and WWE is hopeful that Balor will be back in time for SmackDown on Tuesday, where he’s scheduled to face Dolph Ziggler.
Finn Balor has not been cleared for tonight's match with Shinsuke Nakamura on the Smackville special in Nashville.
Was told that it is a "24-hour bug type situation" and they are hopeful that Balor will be available for SmackDown on Tuesday night.
— John Pollock (@iamjohnpollock) July 28, 2019
Balor was replaced by Ali at the show and Nakamura won with a Kinshasa.

AEW: David Finlay on His Decision to Join AEW Over WWE Was “Easy Choice”, Renee Paquette on Her Praise of Lexy Nair & Arkady Aura’s AEW Careers Growth, Thekla on Working with Skye Blue and Julia Hart & Her AEW Dream Match Opponents
Tommaso Ciampa on His Heel Turn and Attack on Mark Briscoe at 3/7 AEW Collision Show & Declares “The Psycho Killer Is Alive”
Al Snow Issues Official Statement on Medical Emergency Incident Involving Referee Dallas Edwards at 3/12 OVW Rise Show



