This is a bit of a bummer man. I don't know what Summers is thinking or what he's going through, but at the risk of sounding like a jerk, I think it's pretty crappy to quit on your team with three games left in the season...especially when you need to win all three to get bowl eligible. This especially hurts when you consider that he was the best blocking receiver we've got.
I wish him the best and thank him for his efforts, but unless this is due to injury concerns, he should have stuck it out for the next few weeks. I'm not going to go so far as to say it's character defining, but I know I'd be pretty damn upset if any of my teammates had ever quit mid-season.