Welcome to the forums man.
Crawford has a lot of athletic potential that he just hasn't converted into a whole lot of on the field production for one reason or another. A lot of people expected a breakout season a from him a few years ago in his Junior year, but it just never came. He hasn't been able to play a whole lot either, between other guys doing a better job and nagging type injuries he's dealt with throughout his career. He's still got my interest as a late round lottery ticket though, as he's got an interesting combination of length and burst.
He received an invite to the Senior Bowl this year, which was a bit unexpected(from me at least), but he has a chance to really help himself a lot if he's able to stand out down there...and he has the natural ability to do so. He finished the season strong after a slow start, with four sacks in the last four games he played, so maybe that's something for him to build on going into the draft process. He should test very well at the combine too, which always helps.
R.I.P. Junior Seau