According to The Wrestling Observer Newsletter, Jon Moxley is working through an elbow injury, which Dave Meltzer speculates, "may be an infection that he got in Japan."
After returning from his long New Japan excursion, Moxley wrestled Pentagon Jr last weekend before nearly 2000 fans in Poughkeepsie, NY for Northeast Wrestling. Meltzer notes that Moxley was very careful not to take any bumps on his elbow during that match.
Meltzer also adds that some recent Moxley matches that were scheduled as singles were changed to tags, in order to compensate for the injury. The heavily-hyped Pentagon match, however, was kept one-on-one at Moxley's insistence.
Moxley is currently scheduled to go one-on-one with Kenny Omega at All Out, with nothing to indicate right now that that will change. He's also booked for several of the October episodes of the TNT show, including for a match against Shawn Spears on the second episode in Boston.