Hunter was forced out of the game in the bottom of the fourth inning after giving unsuccessful pursuit on Bengie Molina's leadoff smash against John Lackey with the Angels holding an 8-0 lead in what would be a 9-7 victory over the Giants.
X-rays of Hunter's right rib cage, the area of concern, were normal. There was a contusion, and he will be re-evaluated on Tuesday.
"I hate to sit games out, but I don't think I'll be starting these next two games [against the Giants]," Hunter said. "I'm a little sore. Whiplash. That's probably as hard as I've hit a wall."
Racing full tilt, Hunter hit the wall at the 382-foot sign in left-center first with his left shoulder, followed by his head and his right side. As the ball rolled free for a double, Hunter slumped to the ground and stayed down.
Angels manager Mike Scioscia and athletic trainers Rick Smith and Ned Bergert came out to assist and check on Hunter, who remained on his left side, in visible pain, for several minutes. He finally got to his feet and walked off the field, grimacing.
"I was having trouble breathing," Hunter said. "That's why I stayed on my side like that. It was killing me.
"I know it's 8-0, but I can't let a ball drop. Sometimes it's stupid ... but I've got to go get it. It's what I do."
It's one of many reasons why Hunter is so admired by teammates and Scioscia.
"He's sore, naturally," Scioscia said. "He hit that wall about as hard as you can hit it. Right now, it looks like a bruise, fortunately. We'll just go day to day until it's healed.
"Torii plays at one speed. For the most part, he's such a tremendous athlete, he knows how to protect himself. He plays hard. And that lowers his risk of injury. Unfortunately, there's not much you can do when you run into a wall."
Gary Matthews Jr. came in to replace Hunter, who is working on what would be his ninth consecutive Gold Glove Award with another spectacular season. He has saved several games with wall-crunching stabs, including scaling the fence in center in Angel Stadium to take a potential game-turning homer away from the Royals' Miguel Olivo.
Lyle Spencer is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.