Luke Rockhold's return to the Octagon will have to wait.
The former UFC middleweight champion said Monday night in an Instagram story that he has a herniated disk and is out of a scheduled fight with Sean Strickland at UFC 268 on Nov. 6 in New York.
It would have been Rockhold's first bout since July 2019 following more than two years in semi-retirement.
Sources said it's unclear at this time whether or not Strickland will remain on the card. ESPN has Strickland ranked No. 10 in the world at middleweight.
Rockhold (16-5) has dropped two straight and three of his past four, all losses via KO/TKO. The California native was knocked out by Jan Blachowicz, who is now the UFC light heavyweight champion, in a light heavyweight bout at UFC 239 on July 6, 2019. Rockhold, 36, held the UFC middleweight title in 2015 and 2016. He's also a professional model with a Ralph Lauren deal.
Strickland (24-3) has won five in a row and is closing in on title contention. The North Carolina native, who fights out of Las Vegas, is coming off a unanimous decision win over Uriah Hall in a UFC Fight Night main event July 31. Strickland, 30, sports an 11-3 UFC record since his debut in 2014.
UFC 268 will be headlined by a welterweight title rematch between champion Kamaru Usman and challenger Colby Covington. In the co-main event, Rose Namajunas defends her UFC women's strawweight belt against the woman she beat for it, Zhang Weili.