Feeley was originally acquired by Miami for a second round pick in a deal with Philadelphia.
Feeley lost out on the starter's job to Gus Frerotte during training camp and has been relegated to emergency third quarterback status for most of the season.
The Chargers had thought enough of Lemon to keep him on the active roster last year despite having three quarterbacks ahead of him on the depth chart.
The Chargers have clearly begun to think about the future with this deal as the team expects to make a decision between Drew Brees and Philip Rivers this off-season. They are now primed to move forward with thier backup quarterback already in place.
The pick is believed to be a sixth rounder.