"But now I feel fine," he said through his interpreter, Kosuke Inaji. "Just a little headache."
Aoki underwent no tests but said the Giants' medical staff would continue to monitor him through Monday's scheduled off-day.
Aoki, who was hit by a 92 mph delivery on the right side of his batting helmet, realized he could have endured a worse fate.
"I looked at the video and the ball was heading straight for my face," he said.
Said Arrieta, "You never want to see somebody get hit like that. It was obviously not intentional. I was trying to go in with a cutter there. He's on the plate pretty good. It spun away from me a little bit and bored in on him in that situation. I made them call over to make sure he's OK. I hope he's back in the lineup [Tuesday] for them. I hope he's all right."
After being hit, Aoki stood up under his own power but was led from the field toward the Giants' clubhouse by head athletic trainer Dave Groeschner. Angel Pagan ran for Aoki at first base and remained in the game to play center field while Gregor Blanco moved to left.
Aoki was playing his 12th game since he was reinstated from the disabled list July 27 with a fractured right fibula -- an injury caused when he was hit by a pitch from the Dodgers' Carlos Frias. That forced Aoki to miss 28 games.
Referring to that plunking and his latest one, Aoki said, "Hopefully, this is the last time."
Chris Haft is a reporter for MLB.com. Read his blog, Haft-Baked Ideas, follow him on Twitter at @sfgiantsbeat and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.