The Bears placed Freeman on injured reserve in Week 2 after the veteran tore a pectoral muscle in the season opener versus Atlanta, but Freeman suggested Monday that the concussion he also suffered in the Falcons game contributed to the latest suspension.
"I hate to say I'm sorry again, but I'm sorry," Freeman posted on his Twitter account. "I've been on IR all year and you try and stay out of sight, but sorry for the distraction.
"I had been lying to friends, family and loved ones when it came to the question of, 'Are you OK?' Knowing my career may be over due to everything that came with the head injury (that's been purposely downplayed by me), memory loss and all, has actually been a bit of a struggle. That being said there's no excuse to cope with any problems by taking any kind of pills. I don't know my future but a big thanks to the Bears and the NFL, if I would have used their programs and services earlier than I did I wouldn't be in this situation. Sorry again for the distraction."
Freeman -- voted a team captain before Week 1 -- missed four-games last year for a violation of the PED policy but still finished with a team-high 110 tackles.
"We're pretty disappointed," Bears coach John Fox said Monday.
Fox added that he hadn't seen Freeman recently.
Freeman, 31, played four seasons in Indianapolis before he signed a three-year deal with Chicago in 2016. Freeman is under contract through 2018 and scheduled to earn $3.5 million, but he is out of guaranteed money.