Johnson has a guaranteed salary of at least $16.7 million, which will make him the highest-paid cornerback in 2017. The Rams placed the franchise tag on Johnson for the second consecutive season last week.
The Rams and Johnson can discuss a long-term contract until July 15 at 4 p.m. ET., and if no deal is reached by that time, he will play the 2017 season under the franchise tender.
The Rams are expected to wait about a potential contract extension until the team's organized team activities are underway to see if Johnson is a "fit" under new defensive coordinator Wade Phillips, who is switching the team's defensive system from a 4-3 to a 3-4 under new head coach Sean McVay.
"He's definitely a viable player, we need him," general manager Les Snead said of Johnson last week at the NFL Scouting Combine in Indianapolis. "So now we change coordinators, Wade Phillips. It's a different system than we had last year. But I do know this, Wade values corners.
"So, I think what we're going to do with Trumaine, because everybody's new, is hey, we need to work together, live together, see if we're all a fit. Does Tru fit Wade? Does Wade fit Tru? And then at that point because it is obvious from the tag number and what corners get paid, a heavy investment and you want to be right with that. Especially when you go long term. And that's because we got a lot of changing parts."
The 27-year-old Johnson, who made $13.952 million in 2016 playing under the tag, made one interception, 57 tackles and 11 passes defensed in 14 games last season. He missed two games with an ankle injury.
The 6-foot-2, 208-pound Johnson has 16 interceptions in his five NFL seasons, including a career-best seven picks in 2015. He was drafted in the third round by the Rams in 2012 out of Montana.