Torrey Smith sustained a concussion in the third quarter against the Jets on Sunday and had to be carted off the field.
On Wednesday morning, he provided details to KNBR 680.
"You just have to wait until the symptoms go down," Smith explained. "I still have symptoms now. I don't know how long that will be ... it's my first time ever having one like this. I was knocked out. It was pretty bad ... things are getting better so that's a positive sign.
"Our team, I don't feel like they're trying to rush me or anything. They're being very smart. I have a lot of respect for our trainers ... just take it easy and I'll come back when I'm ready."
Smith acknowledged that he had a mild concussion while with the Ravens, "but I've never been knocked out before. So that's pretty scary to look at that."
The wide receiver landed on his head/shoulder area, and remained motionless on the Levi’s Stadium turf for several seconds.
"Definitely some memory loss in there," Smith said. "... It doesn't scare me from wanting to get back out there."
In 12 games this year, Smith has 20 catches for 267 yards and three touchdowns.
The 49ers have three games remaining -- starting with this Sunday at Atlanta.
It's unclear if Smith will play again this season.
"I'm feeling way better," Smith said. "Could have been a lot worse so I'm thankful for that."