The running back told the team's website: "This is the first time since I've been here that I've really seen Tennessee step up like that, as far as free agency and get so many guys.
"It's been good. This year we stepped up and got a lot of guys and solidified with some great draft picks, so it's something to look forward to.
"It's a totally different offensive coordinator. Basically we [are] learning a new playbook right now, and there's a lot of different things going in."
Johnson has recorded over 1,000 rushing yards per season every year since being drafted by the Titans in 2008.