He is not cleared to compete.
New Japan Pro-Wrestling kicked off their Destruction tour on 9/8 and the show is underway as of this writing. Scheduled for the semi-main event was Zack Sabre Jr. defending his World TV Championship against Oleg Boltin.
It has been announced that Boltin will not be able to compete due to a left wrist injury. Per Oleg’s request, Ryohei Oiwa, who is on excursion, will fill in for him in the title bout.
— 新日本プロレスリング株式会社 (@njpw1972) September 8, 2023
Oiwa went on excursion to Pro Wrestling NOAH after being invited there by two-time GHC Heavyweight Champion Kaito Kiyomiya.
Since winning the World TV Title at Wrestle Kingdom 17, Sabre Jr. has had 12 successful defenses of the belt.