Klose said in a statement posted to social media Saturday night that he felt his "hand go numb and neck tighten up" after Stephens pushed him during their weigh-in Friday, and that he continued to not feel well into Saturday.
"After I was pushed by Jeremy at UFC Faceoffs, I immediately felt my hand go numb and neck tighten up," Klose's statement read. "Sean Shelby and the UFC officials sent me to the PI to get worked on by the UFC PT staff for 2 hours. I spent the night eating, rehydrating stretching and even saw the PT staff later that night. I work up early this morning with a migrane/headache, nausea and the only thing that made me feel better was laying in the dark. UFC got me medicine and I rested for a couple hours before getting up and vomiting. It was at that point we called the UFC doctor and he made the decision to send me to the hospital. I'm sorry to everyone who was excited for this fight, I tried to do everything I could to stay in this fight, but these issues are out of my control."
Saturday night's card will proceed with 10 fights.
Stephens (28-18, 1 NC), a perennial featherweight contender, is winless in his past five fights. The 34-year-old San Diego resident has not fought since a May 2020 loss to Calvin Kattar.
Klose (11-2-1) has won three of his past four bouts. The 33-year-old Arizona resident was coming off a knockout loss to Beneil Dariush at UFC 248 on March 7, 2020.