Johnson had previously expressed his desire to retire with the Ravens after playing the past three seasons for the San Diego Chargers.
"I'm excited," Johnson told The Baltimore Sun this offseason. "I had no idea, I didn't know how that whole thing worked. I had just retired and I didn't think anything of it. The response out of Baltimore was awesome. It blew me and my wife away how positive it was. So many people reached out.
"It was pretty flattering to be gone for three years and get so much positive feedback. It's cool to get validation. You always want to know if you're doing things right or wrong and hear it from your teammates and coaches and all the fans."
Johnson, 33, played in the NFL for 12 seasons and was regarded one of the most respected and toughest players in the league. Johnson recorded 20 sacks in nine seasons with the Ravens and missed just one game.
When Johnson announced his retirement last month on Instagram, he saluted the Ravens, who drafted him in the fourth round out of Alabama in 2003.
Johnson was one of the most popular players in franchise history, often drawing comparisons in terms of playing style to longtime nose tackle Kelly Gregg.
"I think the thing that means the most to me, even though I didn't make a Pro Bowl and never made All-Pro, it was more just how you conduct yourself, always being there, always being on time, always doing it hard and the best you can," Johnson said. "When you play a certain way, you play like a Raven. That really means something to the organization and the fans when you play a certain way, the way Terrell [Suggs] and Haloti [Ngata] did, physical, nonstop mindset. They take notice. The thing I'm most proud of is I did it, and other teams might not have known, but the city and the team did. That's the thing I'm most proud of."
Johnson set franchise records with 129 consecutive games played and 80 consecutive starts. (Punter Sam Koch has broken his record for consecutive games with 144 and quarterback Joe Flacco has passed his mark with 112 consecutive starts.)
Johnson had 51 tackles, one sack and a forced fumble last season for the Chargers. He was scheduled to make $5 million next year.
For his career, Johnson played in 184 games, finishing with 506 tackles, 25.5 sacks and 11 forced fumbles.
"I'm happy with my career, I'm content," Johnson said. "I never wanted to be a guy who stayed too long and played until they couldn't walk anymore and be bitter or have resentments. I can't stand that mindset. You see that a lot from ex-players.
"I wanted to go out feeling positive and feeling really good. I played for two fantastic teams. Both had phenomenal teammates and I made great friends. I had great experiences."
Johnson is living in Florida with his wife and two daughters. He's contemplating what he'll do in his retirement. For now, he's relaxing and spending time with his family.
"I'm going to take it a week at a time," Johnson said. "I've got some opportunities. I'm going to weigh my options and see what's best and do something, maybe get involved with the team, maybe do radio, maybe high school coaching. I'm going to sit back and just kind of enjoy not counting down the days until minicamp and training camp."