Bo Jackson -- Raider Nation Is Mourning Todd Christensen

Todd Christensen wasn't your stereotypical football meathead -- he was a gentle soul who loved poetry ... this according to his former Raiders teammate Bo Jackson.

Bo just called TMZ Sports and told us all of Raider Nation is mourning the loss of the legendary tight end, who passed away this morning while undergoing liver surgery.

Jackson played with Christensen for four years and said the guy ALWAYS had a smile on his face.

So, what kind of poetry was Todd into? Check out the clip and find out.

Todd was 57.

NFL legend Jim Plunkett also called in to TMZ Sports to give us his thoughts on Todd Christensen. Check out the audio.