Kelly spent most of the summer rehabbing his foot after April surgery. The Lakers announced the signing on Friday, and though the terms of his contract haven't been released, Kelly will make $490,180 in his rookie season.
The Lakers now have 16 players on the roster, one more than the opening-night maximum of 15. The team is expected to carry 16 to 20 players into training camp, starting with media day on Sept. 28. The Lakers are scheduled to open the season on Oct. 29 at home against the Clippers.
Eleven of the players on the roster have fully guaranteed contracts. The Lakers can open the season with as few as 13 players but might be more likely to keep 14 or 15.
Recent signings include Shawne Williams and Elias Harris, who both have $100,000 of their contracts guaranteed, as well as Marcus Landry and Xavier Henry, whose deals are not guaranteed. It is unclear if any of Kelly's contract is promised.
Kelly, who is 6-foot-11, adds size and shooting ability at the forward position. In his final season at Duke, he averaged 12.9 points with 5.3 rebounds a game.