From his own twitter, the Bears are going to sign yet another offensive lineman to work for a spot:
A childhood dreams are about to come true!! I'm going to sign with my home town Chicago Bears!!!!— AJ Lindeman (@ALinde60) June 13, 2013
A.J. Lindeman is a hometown boy, hailing from Aurora and playing for Waubonsie Valley in high school. Playing for the Toledo Rockets, he clocks in at around 6'6, 300 lbs, and started his final season at right tackle.
EDIT: If you were wondering which strapping young man was released to make room for Lindeman, then wonder no more.
Clearly undrafted, I'll be perfectly honest, a cursory web search reveals very little about Lindeman. He participated in this week's minicamp on a tryout basis, and they must have seen enough to make them think he could at least be a solid practice squad player or some such in the future.
As we can drag up some more details about Lindeman, we'll definitely bring them to you. For now, you can watch this video of his pro day in March, and that might shed some light for you on the player he is.