The 49ers made a roster move just before boarding their flight to Seattle on Saturday, promoting cornerback Asa Jackson to the 53-man roster and waiving cornerback Keith Reaser.
Jackson, who will wear No. 30 on Sunday against the Seahawks, was among the 49ers’ final cuts of training camp. He becomes the 32nd player on the 49ers’ 53-man roster who is new to the organization since the hirings of general manager John Lynch and coach Kyle Shanahan.
Jackson, 27, is a fourth-year pro who was a 2012 fifth-round draft pick of the Baltimore Ravens. He played four games last season with Detroit, including two starts. He had two interceptions in the 49ers' exhibition finale, but the final spot at cornerback to open the regular season went to Reaser.
Reaser was a fifth-round pick in 2014. After missing his entire rookie as he recovered from ACL surgery, Reaser played in 28 games over the past two seasons. He did not appear on defense in the 49ers’ season-opening loss to Carolina last week, but he appeared on 10 snaps of special teams.