David, 23, had two years remaining on his rookie contract, but this move keep him under team control Davis through the 2019 season. San Francisco had $4.0 million in cap space work with as of this past Wednesday.
Davis, 23, was taken in the first-round back in 2010 and is coming off of a very solid season for the 49ers. According to Pro Football Focus, Davis was the No. 10 best offensive tackle in league with solid ratings in both run-blocking and pass protection.