McClain last played in the NFL in 2015 as a member of the Dallas Cowboys. He was suspended indefinitely in 2016 for repeated failed drug tests. Per Zenitz, the linebacker is working with the NFLPA and going through the process of attempting to get reinstated by the NFL.
"I'm nowhere near satisfied with how my professional career has gone," McClain told Zenitz. "That's for myself. That's me looking in the mirror and talking to my boys. Nah, that's not the taste I want to leave in my mouth."
Turning 30 years old on Sunday, McClain said he feels healthier after hip surgery in 2016.
"Every time I got in my linebacker position, it was bone-on-bone grind," McClain said. "Not only do I feel good, I'm recovered and I'm rested. I feel better now because I know I'll be playing with two legs."
The Baltimore Ravens, led by former Crimson Tide great Ozzie Newsome, signed McClain in April 2013. The linebacker, however, stunningly announced his retirement in the following month at the age of 23.
After sitting out the 2013 season, McClain unretired, joining the Dallas Cowboys in 2014, where he played 24 games over two seasons.
Getting reinstated is just one hurdle McClain faces. Finding a team to give him a shot might be an even bigger barrier to the linebacker's comeback.