One day after announcing on Twitter he will "not be playing in the NFL anymore," Antonio Brown says he's returning to college.

The current free-agent receiver posted an Instagram story Monday displaying a four-class schedule at Central Michigan University with the caption "Back to School."

According to Aaron McMann of MLive.com, Brown enrolled in all the classes on Sept. 16 before he was released by the New England Patriots. 

Brown spent three seasons playing at Central Michigan but left before his senior season to enter the NFL draft, where he was a sixth-round pick in 2010. He never graduated from the school but has returned for classes several times since, including in June, per McMann.

His newest schedule includes classes in English, religion, sociology and management, all of which are online.

It's unclear if the 31-year-old had been planning to complete the classes while playing the NFL season, but he now has more time after being released by the Patriots. He spent only 11 days with the team during a stretch that included a civil suit alleging sexual assault, a second accusation of sexual misconduct and intimidating texts sent to one of his accusers.

This came after a short stint with the Oakland Raiders that ended with him being released before ever playing a game.

The NFL announced Friday that any team is free to sign Brown, but the league will continue to investigate the allegations against him.