The list also includes starting center John Sullivan, starting outside linebacker Connor Barwin, valuable slot corner Nickell Robey-Coleman and rotational defensive tackle Tyrunn Walker.
Of those, Watkins seems the most likely candidate to play 2018 under the franchise tag distinction. Coming off a down year statistically, Watkins isn't in line for a massive long-term contract, but could better position himself for a bigger payday if he can increase his numbers on a one-year deal.
The Rams will move on from Johnson after their acquisition of Marcus Peters from Kansas City. They would like to get Joyner and Robey-Coleman back and, with more than $40 million in cap space, they have the necessary flexibility to make that happen.
Unit-by-unit depth chart as of Super Bowl LII. Injured players listed as starters if that was their status when injured.
*Asterisk indicates player ended 2017 season on injured reserve.
TIGHT ENDS (C): Starter - Tyler Higbee. Backups - Gerald Everett, Derek Carrier (UFA), *Temarrick Hemingway.
RUNNING BACKS (A): Starter - Todd Gurley II. Backups - Malcolm Brown, Lance Dunbar (UFA), Justin Davis, FB *Zach Laskey, *Lenard Tillery.
OFFENSIVE LINEMEN (B-plus): Starters - LT Andrew Whitworth, LG Rodger Saffold (UFA), C John Sullivan, RG Jamon Brown, RT Robert Havenstein. Backups - T Darrell Williams, T Cornelius Lucas, C/G Austin Blythe, C/G Aaron Neary.
DEFENSIVE LINEMEN (A): Starters - DT Michael Brockers, RDE Aaron Donald, LDE *Matt Longacre, T *Dominique Easley (UFA). Backups - DE Morgan Fox, NT Ethan Westbrooks (UFA), NT Tyrunn Walker, NT Tanzel Smart.
LINEBACKERS (B): Starters - OLB Connor Barwin (UFA), OLB Robert Quinn, ILB Mark Barron, ILB Alec Ogletree. Backups - OLB Samson Ebukam, ILB Bryce Hager, OLB Garrett Sickels, ILB Cory Littleton, OLB Cameron Lynch.
DEFENSIVE BACKS (B): Starters - CB Trumaine Johnson (UFA), CB *Kayvon Webster, SS John Johnson, FS Lamarcus Joyner (UFA). Backups - CB Troy Hill, CB Nickell Robey-Coleman (UFA), CB Kevin Peterson, CB Isaiah Johnson, S Cody Davis (UFA), S Blake Countess, S *Marqui Christian. Addition: CB Marcus Peters (to be acquired from Chiefs).
SPECIAL TEAMS (A): K *Greg Zuerlein, K Sam Ficken, P Johnny Hekker, PR/KR Pharoh Cooper, LS Jake McQuaide.