For the second time this year, TJ Grant has been forced to remove his name from a title for for the UFC lightweight championship.

Grant, who suffered a concussion in training earlier this summer, is still experiencing issues from the injury. He was set to face Benson Henderson last month, but Anthony Pettis stepped in and defeated Henderson.

UFC officials planned to pair Grant with Pettis at UFC on FOX 9, but that slot now goes to Josh Thomson.

Grant took to Twitter to explain what went down:

“Hey people. Quick update. Unfortunately I won’t be fighting (Anthony) Pettis on Dec. 14,” he wrote. “I am sill not yet 100-percent (and) can’t commit to fight. UFC is going with someone else instead.

“It sucks but it is the best for both myself and the UFC. Please don’t worry. I’ll be back and if I gotta fight someone else to get back to where I wanna be then that’s what I’m gonna do. I’m not bitter.”

Grant vaulted into title-contention by finishing Gray Maynard.