Los Angeles will need to decide who to apply the tag on ahead of the March 1 deadline.
The franchise tag for cornerbacks is expected to rise to $13.92 million, according to ESPN's Field Yates.
Jenkins recorded 64 tackles and three interceptions last season, and is known around the league for his ball skills, and willingness to take risks in coverage.
Johnson is coming off a breakout season, where he amassed 71 tackles and a career-high seven interceptions. The 26-year-old held quarterbacks to an abysmal 55.3 passer rating, the second-best total in the NFL, according to Pro Football Focus.
Either Jenkins or Johnson would become some of the most highly sought-after cornerbacks in a strong class this spring, if they hit the open market.