 He competed with Chris Culliver, Tramaine Brock, Perrish Cox, Chris Cook, Kenneth Acker, and Darryl Morris throughout training camp in for the job as the starting cornerback.Head coach Jim Harbaugh named Johnson the fifth cornerback on the depth chart, behind veterans Tramaine Brock, Chris Culliver, Perrish Cox, and Chris Cook.He made his professional regular season debut in the San Francisco 49ers' season-opener at the Dallas Cowboys and recorded two solo tackles and two pass deflections in their 28–17 victory.