The wide receiver failed to make a reception during the regular season with the Super Bowl runners-up last campaign, having featured in just three games during his rookie year.
The 23-year-old told the 49ers' official website: "I'm just trying to do what I can to help this team win. I'm trying to do my part. We're all trying to make plays for this team. If the ball is thrown our way, we have to go get it. That's what we're here to do.
"I feel real good. I feel a lot better than I did last year at this time, but I feel great, I feel comfortable in the offense and so we'll see what happens.
"Honestly, every practice, my mindset is I don't want to wait until the game to be ready, I want to be ready for the practices. I don't want to wait until Thursday comes around and I'm trying to get ready, I'm doing that right now at camp."
The 49ers picked Jenkins with their first-round draft pick last year.