It appears that the injury that has sidelined former IWGP, NWA and TNA Champion AJ Styles from recent New Japan Pro Wrestling events is the same one that kept him off the recent Ring of Honor television tapings.
Styles is dealing with a lower back issue, one that limited him to a non-wrestling appearance at last month's ROH tapings. He took a little time off to heal up for the NJPW tag league, but has been held out of several days worth of shows. Styles continues to travel to the shows, however, as he's been seen by several fans arriving at the shows.
Styles told New Japan's bi-monthly magazine that the injury was caused by overworking himself on the independent circuit in 2015.