A lumbar hernia is to blame for knocking a lightweight fight from the UFC's return to Brazil next month.

That's the diagnosis for Rony Jason (13-3 MMA, 3-0 UFC), and the Brazilian MMA Athletic Commission (CABMMA) has ruled him out of his UFC Fight Night 29 bout against Jeremy Stephens (21-9 MMA, 8-8 UFC) next month.

According to CABMMA, an MRI requested by CABMMA's doctor revealed the injury and Jason's participation in the event was shut down. A time table for his return is not yet known.

UFC officials have not yet announced his injury, or whether a replacement for Stephens will be sought for the card.