In a string of profanity-laced tweets, McClain said his brain has been "crazy" since he retired from the NFL in 2014 and claimed the league didn't care about the well-being of its players.
"I have to get my head checked. Playing fullback since high school. Its takes too f------ much to do anything. My brain is f------ tired," the 34-year-old tweeted Saturday. "@NFL I need some help with this s---. Dark times and its showing. F------ help me please!! They dont care I had to get lawyers man!"
"Need to tell my story of how my head is crazy and how football did it.... Please someone help me get this out the @NFL puts paperwork in [our] faces and thats it," he added in a subsequent tweet.
McClain, who spent the bulk of his 7-year career playing for the Baltimore Ravens, suggested that the NFL had ignored his cries for help and claimed it would be more willing to "aid" him if he played quarterback, a higher position than fullback.
He recorded a career 1,310 rushing yards and 13 touchdowns before retiring in 2014.
"Watch how fast they come to aid if I was som3 QB or anything but no I was f------ fullback that did it all," he tweeted. "@NFL I need help and I need the process to speed the f--- up im about to crash out and its paperwork I dont wanna hear it."
Several of the baller's 32,000 followers reached out to ask if he was OK and if he needed resources for suicide prevention. He admitted that he wasn't doing well, but he said he would keep on fighting.
"Swear Queen Imma be solid. Had a moment but Imma fight this thing head on. Love the game but do the game love us back??? In due time I will see Queen. Always Love," he told one concerned follower. "God be with me. I got this I got this," he added in another tweet.
The tweetstorm came just hours before 29-year-old Indianapolis Colts quarterback Andrew Luck shocked the sports world with the announcement of his early retirement on Saturday due to concerns about the game's impact on his health.
Luck retired with two years remaining on his current contract, saying he was tired of a never ending "cycle of injury, pain [and] rehab."
"I felt stuck in it, and the only way I see out is to no longer play football. It's taken my joy of this game away," Luck told reporters Saturday. "I’ve been stuck in this process, I haven’t been able to live the life I want to live, it’s taken the joy out of this game."
A spokesperson for the NFL did not immediately respond to ABC News' request for comment.