The 53-year-old defended his cart usage in the media on Tuesday and Wednesday.
"I'd love to walk," Daly told Josh Peter of USA Today on Tuesday. "I've done it for years. I think it's a disadvantage to ride, anyway. Trust me, I just can't."
When asked about the cart, Tiger Woods said the following at his pre-tournament press conference:
Woods played 91 holes on a broken leg and torn ACL en route to winning the 2008 U.S. Open at Torrey Pines.
That stands as a superhuman feat of perseverance and strength in sports, but Daly's osteoarthritis in his right knee is extremely painful.
"Osteoarthritis is a tough thing, brother. If my knee was broke, I would have had it fixed. But my situation is totally different. It's painful as hell is all I can say. As was Tiger's, I'm sure."
Daly, who also suffers from Type 2 diabetes and high blood pressure, reiterated his cart-riding stance on Wednesday, per Tom Canavan of the Associated Press.
"Trust me, I hate riding in the cart," he said. "If I could walk, I would do it. I could probably walk four holes and be done. The thing swells up so bad."
Daly tees off on the 10th hole with fellow PGA Championship winners Y.E. Yang and Rich Beem at 12:54 p.m. ET on Thursday.