He was kept off of this week's episode of Smackdown, and has been pulled from this weekend's slate of house shows.
Styles has been one of WWE's most consistent performers since his January debut, but the star - who turns 39 next month - is currently paying the price for years of working an ultra-athletic style.
Last December, Styles's back was causing him so much pain that he was forced to withdraw from New Japan's World Tag League tournament. Styles was considered questionable for Ring of Honor's Final Battle show, where he was scheduled to wrestle ROH World Champion Jay Lethal in the main event, and New Japan's Wrestle Kingdom, where he would challenge IWGP Intercontinental Champion Shinsuke Nakamura. Ultimately, "The Phenomenal One" made both bookings, taking part in classic matches.
Many assumed that Styles would take time to recover following his last New Japan match on January 5, but three weeks later he debuted for WWE in the Royal Rumble.
Since then, he's delivered his trademark fantastic matches, first feuding with Chris Jericho and then emerging as top contender to Roman Reigns's WWE Championship.
