"He's got a serious recovery that he's got to go through, and it's going to take awhile," Carroll said.
Thomas will not have to undergo surgery for the injury, a source informed of the situation told NFL Network Insider Ian Rapoport.
"This game has been so good to me no regrets," Thomas tweeted after exiting the game. "A lot is running through my mind including retirement thanks for all the prayers."
Thomas wrote that tweet roughly 30 minutes after being helped off the field after suffering the injury, when emotions were running high. Thomas collided with teammate Kam Chancellor in mid-air as Thomas made a great breakup of a pass. Thomas was unable to put pressure on the leg after the injury.
After his team's 40-7 win, Carroll addressed the tweet: "I will say that a lot was running through his mind when he said that, I think it tells you exactly what he's talking about. I saw him in the training room tonight and at halftime and ... I'm not so sure about that either but I'm not surprised that he said something like that. Earl's apt to go ahead and say something that might surprise you and he did."
It's a brutal turn of events for Thomas, who was enjoying another terrific year. After a relative down season in 2015, Thomas and Chancellor were once again the best safety tandem in football this season. Steven Terrell replaced Thomas in the lineup Sunday.
It was only three weeks ago that Thomas knocked Patriots tight end Rob Gronkowski out of a game with a vicious hit to the midsection. Since then, Gronkowski was lost for the season due to an unrelated injury and Thomas has now been felled by this injury. In a game Sunday night where Panthers linebacker Luke Kuechly watched from the sideline because of a concussion, we can't help but think that the NFL is losing too many star players as we hit the stretch run.