Ahead of the FedEx Cup play-offs curtain raiser The Barclays, starting Thursday, Kuchar said his fitness had returned after a tight back forced him to pull out of the major at Valhalla Golf Club earlier in August.
Unlike 14-time major winner Tiger Woods, who remains sidelined due to his troublesome back, Kuchar's issue was his first in his 14-year professional career.
"It was an odd thing. I've never had to pull out of a tournament before. I've never had an issue that came up that kept me from playing. It was particularly bad timing," the world number seven said.
"There's never a good time to come down and have an injury and have something take you away where you wasn't play, but the PGA Championship was certainly a week that I was looking forward to.
"I had played a couple practice rounds at Valhalla and I was feeling pretty good my game. That was too bad.
"But [I've] had 10 days now to try to get healthy and feel really good."
Kuchar, 36, said he first felt his back tighten after a day spent on his feet shopping for one of his kids' birthday parties, before sitting idle in his car for an extended period.
And the seven-time PGA Tour winner said the injury caused him to fear the worst.
"It's interesting, whenever you're ill, injured, it crosses your mind that you may never be healthy again, and then now I'm healthy and I think, I'm never going to get injured again," Kuchar said.
"I feel good. I feel like I'm 100 per cent. It's funny how little setbacks can feel so different to you.
"I went from feeling like, 'gosh, I may never be able to really play well again' to 'there's nothing stopping me now'."
Kuchar, the 2010 Barclays champion, is paired with fellow American Jim Furyk and Spain's Sergio Garcia for Thursday's opening round at Ridgewood Country Club in Paramus, New Jersey.