This is one whose career is a "what could've been" story, because he flashed some excellence really briefly, but...
Remember WR Patrick Jeffers?
We traded for him after training camp, if I recall right, in 1998. I'm not even sure what we gave up. Future considerations or something, basically nothing.
He started the year on the scout team and learning the offense, basically non-existent. Then he came on and averaged almost 20 yards per catch. And was one of the few guys who played well in the playoffs.
We let him walk because we didn't want to match the $1M offer sheet, deciding the one million bucks and a late round compensation pick were worth more to us than him. So he went to Carolina and had a monster season, averaging 17 yards per catch and scoring 12 touchdowns. He was an amazing weapon, showing the flashes he'd demonstrated late in 1998 could be stretched out into a full season. Part of a pretty unbelievable season by Steve Beuerlein, of all people.
Then he suffered an injury the next preseason and his career was basically over right after he'd blown up.