"You'll see my progress on the field next year," Bosa told ESPN's Josina Anderson on Monday night. "Tell them I'm gonna be better."
Bosa lived up to the hype as a rookie, collecting nine sacks, one interception and one forced fumble in 2019 to earn a Pro Bowl selection. He added four more sacks during San Francisco's run to Super Bowl LIV.
Pro Football Focus' Ben Linsey ranked him as the 10th-best player under the age of 25 in the NFL.
A 2020 return was out of the question, with the team instead looking to have the former Ohio State star ready for the 2021 campaign.
Bosa figures to be a large part of the 49ers defense in the years ahead. That said, his recovery from knee surgery will loom large for the franchise until the 23-year-old can show he remains a devastating force along the defensive line.