I don't like drafting injured guys either but these days guys come back from knee surgery pretty well.It is unlikely to bother him long term.he might not be ready to go in September but he will probably be able to get on the field next season.
And I am a big Dotson fan, it might be better to have a bigger WR to team with Waddle but I like the idea of teams chasing multiple explosive guys around and dealing with both Dotson and Waddle would be a chore.
Plus Dotson makes contested catches like a bigger WR, he just has a knack for coming down with the ball.
I am starting to worry that he will not make it to #29.